Physics MCQs For Job Test Preparation Set. 2

1 - "God Particle" is





Higgs Boson

2 - 0.001 kg mass will be equivalent to





25.00 GWh

3 - A . C and D . C have the same





heating effect through a resistance

4 - A . C can not be used for





Magnetizing iron

5 - A . C cannot be used for





magnetizing and electroplating

6 - A 25eV electron has a speed of





3 x 106m/sec

7 - A 5 Degree F capacitor has a potential difference across its plates of 200 volts. The charge on the capacitor is





10-5 C

8 - A capacitor is a perfect insulator for





direct current

9 - A capacitor of capacitance 30 Degree F is charged by a constant current of 10mAIf initially the capacitor was uncharged what is the time taken for the potential difference across the capacitor to reach 300V?





0.9sec

10 - A certain stress applied to an elastic material produces a certain strain in it. If the elastic limit is not exceeded the energy gained per unit volume of the material is given by





(Stress / strain)

11 - A changing magnetic flux produces around itself an induced





Electromagnetic force

12 - A charge of 0.10C accelerated through a potential difference of 1000V acquires kinetic energy





100J

13 - A choke is used as a resistance in





AC circuits

14 - A closed surface contains two equal and opposite charges. The net electric flux from the surface will be





zero

15 - A completely filled band is called





Core band

16 - A device based on photoelectric effect is called





photo cell

17 - A device for producing high velocity nuclei is





linear accelerator

18 - A dynamo converts





mechanical energy into electrical energy

19 - A ferromagnet will become fully magnetized at





Alternating current at its peak value

20 - A fuse is placed in series with the cireuit to protect against





over heating

21 - A galvanometer basically is an instrument used to





detect current in a circuit

22 - A hollow metallic sphere of 8cm diameter is charged with 4 x 10 8





900 volts

23 - A light ray travelling from denser to rarer medium at an angle of incidence more than critical angle of concerned media pair suffers.





Total internal reflection

24 - A magnetic compass will be deflected if it is kept near a





charge in motion

25 - A magnetic field





exerts a force if the charged particle is moving perpendicular to the magnetic field lines

26 - A mass spectrograph (spectrometer) sorts out





ions

27 - A metal rod of 25 cm length is moving at a speed of 0.5/sec in direction perpendicular to 0.25T magnetic field. Emf produced in the rod is





0.03125 volt

28 - A moving coil galvanometer of resistance 100 ohm gives half scale deflection for a current of 20mA. What will be the potential difference across it?





2 volt

29 - A particle having the mass of an electron and the charge of a proton is called a





positron

30 - A particle of mass m charge q and speed V enters a uniform magnetic radius r. The radius r of the circle is





directly proportional to m

31 - A photon is





a quantum of electromagnetic radiation

32 - A photon of wave length 900nm behaves like a particle of mass





2.46 x 10-36kg

33 - A pure variable resistor is connected in series with a pure capacitor of fixed capacitance. The impedance of the circuit





Increases

34 - A rubber cord of cross-sectional area 2cm2 has a length of 1m. When a tensile force of 10N is applied the length of the cord increases by 1cm. What is the youngs modulus of rubber?





5x106 Nm-2

35 - A sensitive galvanometer gives full-scale deflection with 100 mV. If the resistance of the galvanometer is 50 Ohm the maximum current that can flow through safely is





2.0 mA

36 - A small coil lies inside a large coil. The two coils are horizontal concentric and carry currents in opposite directions. The large coil will experience





No resultant force

37 - A small gap is left at the joints of rails in a railway track to





Avoid the tracks being distorted due to seasonal temperature variation

38 - A three dimensional image is obtained by





Seanning electron microscope

39 - A uniform steel wire of length 4m and area of cross-section 3x10-6m2 is extended by 1mm by the application of a force. If the youngs modulus of steel is 2x1011 Nm-2 the energy stored in the wire is





0.75J

40 - A vacant or partially filled band is called





Conduction band

41 - A wheat stone bridge is said to be balanced when





potential difference across galvanometer branch is zero

42 - A wire having very high value of conductance is said to be





very good conductor

43 - A wire is stretched by a force F which causes an extension





The energy stored in the wire is

44 - A wire obeys Hooks law is of length 11 when it is in equilibrium under a tension F





(F1+F2) (12-11)

45 - A wire of uniform area of cross-section A length L and resistance R is cut into two parts. Resistivity of each part





remains the same

46 - A wire suspended vertically from one end is stretched by attaching a weight of 20N to the lower end. The weight stretches the wire by 1mm. How much energy is gained by the wire?





0.01J

47 - Acceptor and donor impurities donate





p-carriers and n-carriers respectively

48 - According to which one of following law the density of atom is uniform?





J.J.Thomson model

49 - After traveling through a vacuum a photon of light entering into some transparent denser medium. Thus the energy of light





Remains same

50 - All electrical appliances are connected in parallel to each other between the main line and neutral wire to get





different current but same potential difference

51 - Ammeter connected in an AC circuit measures





rms value of current

52 - An aeroplane of wingspan 10m flies from the equator towards the North Pole. The wings are perpendicular to the vertical component of the earths magnetic field (B = 4x10-5T). At maximum speed an emf of 96mV is induced across the wing tips. The maximum spee





384msec-1

53 - An alternating current of r.m.s value of 4.0 A and frequency 50Hz flows in a circuit containing 10 ohm resistor. The peak current is then





5.66A

54 - An alternating current or voltage





changes its magnitude continuously and reverses its direction of flow after regularly recurring intervals.

55 - An alternating current or voltage





changes its direction again and again

56 - An ammeter measures the total current flowing through a circuit when it is connected





in series with the circuit

57 - An electric charge at rest produces





only an electric field

58 - An electric current induced within the body of a conductor when that conductor either moves through a non uniform magnetic field or in a region where there is a change in magnetic flux is called





Eddy current

59 - An electric field can deflect





none

60 - An electric iron is marked 20 volts 500W. The units consumed by it in using if for 24 hours will be





12

61 - An electromagnetic wave consists of





Electric and magnetic fields moving perpendicular to each other

62 - An electron enters a region where the electric field E is perpendicular to the magnetic field





B = eE/V

63 - An immersion heater of 400 watts kept on for 5 hours will consume electrical power of





2KWh

64 - An inductor may store energy in





its magnetic field

65 - An instrument which can measure potential without drawing any current is





cathode ray oscilloscope (CRO)

66 - An observer shoots parallel to a meter stick at very high (relativistic) speed and finds that the length of meter stick is





less than one meter

67 - An OP-AMP comparator is a circuit that compares the signal voltage on one of its inputs with a _





Reference voltage on the other

68 - An OP-AMPs can amplify





A . C .

69 - Antimatter consists of





all of above

70 - Any alteration produced in shapes length or volume when a body is subjected to some external force is called





Deformation

71 - As the temperature of black body is raised the wavelength corresponding to maximum intensity





shifts towards shorter wavelength

72 - Average distance covered by ?-particle in air before its ionizing power ceases is called its





range

73 - Average energy required to remove one nucleon from the nucleus is called





binding energy per nucleon

74 - Bracket series is obtained when all transition of electron terminate on





4th orbit

75 - capacitor is to have an energy content of 20J it must be placed across a potential difference of





2 volts

76 - CFC is used in





all of above

77 - Charge on an electron was determine by





Millikan

78 - Charge on neutron is





zero

79 - Choose the correct statement. In the case of AC circuit ohms law holds for





All of the above

80 - Circuit which gives continuously varying potential is called





potential divider

81 - cmf generated by A . C dynamo depends upon





all of above

82 - Coercive force is the force which opposes





Demagnetization

83 - Coil of a galvanometer is suspended in a radial magnetic field so that the deflecting torque on the coil is always





BINA

84 - Compton effect proves the





Photon theory of light

85 - Current produced by moving the loop of wire across a magnetic field is called





induced current

86 - Danger signals are generally red as red light





Undergoes least deviation

87 - Davison Germer experiment indicates





election diffraction

88 - Depletion region of a junction is formed





during the manufacturing process

89 - Diameter of an atom is approximately





10-10m

90 - During an encounter with an atom ?-particle knocks out





electrons

91 - During fission process a large amount of





nuclear energy is released

92 - During fusion of hydrogen into helium





energy is released

93 - Electric charge of 100 ?C is 13cm apart from another charge 16.9 Degree C electric force between them is





900N

94 - Electric flux linked with a surface will be maximum when





the surface is held perpendicular to the electric field

95 - Electric force between two point charges in air or vacuum is F. If we replace air or vacuum by an insulator (dielectric) of relative permitivity Cr the force between the charges will





decrease

96 - Electric intensity at infinite distance from the point charge is





zero

97 - Electric intensity being a vector quantity always points





along the direction of force experienced by a unit positive charge

98 - Electrical energy is converted to heat at the rate of





I2R

99 - Electrical energy is measured in





kilowatt hour

100 - Electromagnetic waves emitted from antenna are





Transverse

101 - Electromagnetic waves transport





Energy

102 - Electromagnetic waves travel in free space with the speed of





?-rays

103 - Electron cannot exist in the nucleus it is confirmed by observing that





The velocity of electron must be very high according to uncertainty principle.

104 - Electron moves in the orbit as





Standing wave motion.

105 - Electrons





cannot exist inside the nucleus

106 - Electrons present in p-type material due to thermal pair generation are





minority carriers

107 - emf induced in a circuit according to Faradays law depends on the





rate of change of magnetic flux

108 - Energy liberated when one atom of U-235 undergoes fission reaction is





200MeV

109 - Energy needed to magnetize and demagnetize is represented by





Hysteresis loop area

110 - Energy stored in a magnetic field is given by





LI2/2

111 - Equipotential planes are





parallel to one another

112 - Equivalent capacitance is greater than individual capacitances in





parallel combination

113 - Excited atoms return to their ground state in





10-8s

114 - Fission chain reaction in a nuclear reactor can be controlled by introducing





cadmium rods

115 - For chain reaction to build up the size of the radioactive target should be





greater than the critical size

116 - For confinement of electron in a box of radius 10-14m the electron speed should be





Should be greater than speed of light.

117 - For electroplating we use





A D . C source

118 - For every action, there is an equal and opposite reaction, is Newton's





Third law

119 - For long distance transmission the transformer used is





Step up

120 - Formation of large molecule by joining small molecules is





Polymerization

121 - Forward current through a semi conductor diode circuit is due to





majority carriers

122 - Galvanometer is a very sensitive device with





very low damping

123 - Gamma rays can cause





Gene mutation

124 - Gas thermometers are more sensitive than the liquid thermometers because the gases





Have large coefficient of expansion

125 - Geiger counter is suitable for





slow counting

126 - Green house effect is the heating up of the Earth's atmosphere which is due to





The infra-red rays

127 - Half life of radium is 1590 years. In how many years shall the earth loss all its radium due to radioactive decay?





never

128 - Heating a magnet will





weaken it

129 - Hole is equivalent to





a positive charge

130 - Holes can exist in





Semi conductors

131 - How much heat does a 40 W bulb generates in one hour?





144000J

132 - Hydrogen atom does not emit X-rays because





it has a single electron

133 - Identify the correct statement about minority carriers





holes in n-type and free electrons in p-type

134 - If 1 ampere current flows through 2m long conductor the charge flow through it in 1 hour will be





3600C

135 - If a charged rod is brought closer to a gas filled balloon then





Radius increase

136 - If a current carrying solenoid is suspended freely it will





come to rest in N-S direction

137 - If a diffraction grating is placed in the path of a light beam it reveals





Wave property

138 - If a glass plate is inserted in between the plate of a capacitor in series with a lighted bulb the brightness of the bulb





Brightness increases

139 - If a material object moves with speed of light its mass becomes





infinite

140 - If an electrons is allowed to move along the field in a non uniform electric field then it will follow





Straight line

141 - If capacitance of L-C circuit is made four times then frequency of the circuit becomes





One half

142 - If free space between the plates of a capacitor is replaced by a dielectric





The potential difference decreases but both capacitance and energy increase

143 - If metallic conductor is charged negatively then its weight





Increases for a while

144 - If mica sheet is placed between the plates of a capacitor the capacity





increases

145 - If one or more of the neutrons emitted during fission cab be used to build up further fission then the reaction is self sustained and is known as





chain reaction

146 - If the coil is wound on an iron core the flux through it will





increase

147 - If the density of atoms remain same along any direction in a crystal is called





Homogeneity

148 - If the distance between the two point charges become half then force between them becomes





four times

149 - If the secondary coil has Ns turns and the primary Np turns the relation between secondary and primary voltages is given by





Vs/Vp = Ns/Np

150 - If the temperature of a place increases suddenly, the relative humidity





Decreases

151 - If the wavelength of incident radiation is increased in photoemission then





The average kinetic energy of the photoelectrons decreases.

152 - If two charges are increased by two times then force





Increases 4 times

153 - In a charged capacitor the energy resides in





electric field

154 - In a half-wave rectifier the r.m.s. value of the A . C .component of the wave is





More than D . C .value

155 - In a multi range ammeter as the range increases





shunt value decreases

156 - In a non-uniform electric field a polar molecule will experience





both series and parallel combinations

157 - In a photoelectric effect monochromatic light is incident on a metal surface. If the incident light of twice the intensity but of same wavelength the kinetic energy of the emitted electron





Remains same

158 - In a refrigerator what produces the cooling ?





None of these

159 - In a refrigerator, the cooling system should always be





At the bottom

160 - In a semiconductors the charge carriers are





Electron and holes both

161 - In an LCR series circuit, if V is the effective value of the applied voltage VR is the voltage across R VL is the effective voltage across L & Vc is the effective voltage across C then





V2 = VR2+(VL-VC)2

162 - In an X-ray tube electrons each of charge e are accelerated through V potential difference allowed to hit a metal target. The wavelength of the X-rays emitted is





he/ev

163 - In beta decay what is emitted?





Electron

164 - In Compton scattering the change in wave length is max if





angle of scattering is 180 Degree

165 - In Davisson-Germer experiment the diffracted proton from crystal shows





Wave property

166 - In electron microscope electric & magnetic fields are used as





Converging source of electrons.

167 - In electron microscope we use energetic particles because of





Wavelength is very short.

168 - In forward bias the width of potential barrier





Decreases

169 - In full wave rectification the output D . C .voltage across the load is obtained for





The complete cycle of input A . C .

170 - In half-wave rectification the output D . C .voltages is obtained across the load for





The positive half cycle of A . C .

171 - In He-Ne laser the lasing action is produced by





Ne only.

172 - In hydrogen spectrum which one of the following series lies in the ultraviolet region?





Lymann series

173 - In laser production the state in which more atoms are in the upper state than in the lower one is called





Inverted population.

174 - In liquid metal fast breeder reactor the type of uranium used is





92U238

175 - In liquids and gases the current is due to the motion





both negative and positive charges

176 - In mirrors the back surface is coated with a thin layer of :





Silver

177 - In normal state of energy the incident high energy photons will be





Absorbed.

178 - In n-p-n transistor, p works as





base

179 - In nucleus of uranium the number of neutrons will be





different for different isotopes

180 - In obtaining an X-ray photograph of our hand we use the principle of





shadow photograph

181 - In p-n-p transistor the collector current is





slightly less than emitter current

182 - In severe winter, in cold countries water pipes burst because





Water expands on freezing

183 - In simple cube one atom or molecule lies at its





Eight corners

184 - In the transistor schematic symbol, the arrow





is located on the emitter

185 - Inductors acts as a short circuit for





DC

186 - Internal resistance is the resistance offered by





source of e m f

187 - Lagging of changes in the magnetization of a substance behind changes in the magnetic field as the magnetic field is varied is known as magnetic





Hysteresis

188 - Linear momentum of a photon is





zero

189 - Long distance transmission is easy for





A . C voltage

190 - Magnetic compass needle will be deflecting if it is kept near





Accelerating charge

191 - Magnetic flux and flux density are related by





magnetic flux = flux density x area

192 - Magnetic force acting on a unit positive charge moving perpendicular to the magnetic field with a unit velocity is called





magnetic induction

193 - Many of the semi conductors are crystals of the type





Face centred cubic

194 - Mark the wrong statement.





Newtons laws of motion are valid in an accelerated (non inertial) frame of reference

195 - Mass defect per nucleon is





packing fraction

196 - Mass of neutron is





1.67 x 10-27 kg

197 - Materials in which valence electrons are tightly bound to their atoms at low temperature are called





Insulators

198 - Materials that undergo plastic deformation before breaking are called





Ductile

199 - Maximum frequency in the spectrum from X-ray tube is directly proportional to the





The kinetic energy of the incident electron i.e. the potential difference through which they are accelerated.

200 - Minimum current required to produce a deflection of 1 mm on a scale at a distance of 1 meter is





current sensitivity

201 - N/C =





V/m

202 - Neutron and proton are commonly known as





nucleon

203 - Newton's first law of motion gives the concept of





Inertia

204 - Non inductive resistances are used in decreasing





Self inductance

205 - Non-inverting amplifier circuits have





A very high input impedance

206 - Nuclear Fission is caused by the impact of





Neutron

207 - Nuclear forces exist between





all of the above

208 - Nuclei having the same mass number but different atomic number are





Isobars

209 - On the basis of band theory of solids the semiconductors have





A completely filled valence band a partially filled conduction band and a narrow forbidden band

210 - One amu is equal to





all of above

211 - One kilowatt hour is the amount of energy delivered during





one hour

212 - Pair production cannot take place in vacuum as





momentum is not conserved

213 - Pair production cannot take place in vacuum as ________ is not conserved





momentum

214 - Pair production takes place in the vicinity of a heavy nucleus so that





all of the above

215 - Photocopier and inject printer are dealt in





Electrostatics

216 - Photon of highest frequency will be absorbed when transition takes place from





1st to 5th orbit

217 - Pipelines in cold countries often burst in winter, because





Water freezes and expands in its volume

218 - p-n junction when reversed biased acts as a





off switch

219 - Potential difference is the work done in moving unit positive charge form one point to another





against electric intensity

220 - Power loss in actual transformer is due to





Eddy currents and magnetic hysterias

221 - Production of heat due to an electric current flowing through a conductor is given by





Joule effect

222 - pure resistor circuit the voltage and current are





They have zero phase difference

223 - Radiation produced from TV picture tube is





X-rays

224 - Radiation with wavelength longer than red lights





infra red radiation

225 - Radioactive materials can be identified by measuring their





half life

226 - Radioactivity is a ______ (A) Spontaneous activity (B) Chemical property





C & A

227 - Radiocarbon dating technique is used to estimate the age of





Fossils

228 - Railway tracks are banked on curves so that





Necessary centripetal force may be obtained from the horizontal component of the weight of the train

229 - Ratio of the weight of H-atom to that of an electron is approximately





1836

230 - Reciprocal of resistivity is called





conductivity

231 - Reflecting mirrors in laser is used to





Further stimulation

232 - Resistance of a conductor depends upon





all of above

233 - Resistance of a super conductor is





zero

234 - Resistance of a wire on increasing its temperature will





increase with rise in temperature

235 - Resistance of an ideal insulator is





infinite

236 - Rest mass of a photon is





zero

237 - Reverse process of photoelectric effect is





X-rays production

238 - Selenium becomes a conductor in light so it behaves like





Photodiode

239 - Self inductance of a coil depends upon





all

240 - Semi-conductor germanium and silicon are





tetravalent

241 - Semi-conductors with donor atoms and free electrons belong to the type





n

242 - SI unit of flux density is





NA-1m-1

243 - SI unit of permitivity of free space is





N-1m-2C2

244 - Specific resistance of a wire





will depend on the type of material of the wire

245 - Stopping potential for a metal surface in case of photoelectric emission depends on





the frequency of incident light and work function of the metal surface

246 - Sum of the masses of constituent nucleons as compared to the mass of the resultant nucleus is





greater than 82

247 - Terminal potential difference of a battery is greater than its emf when





the battery is charged

248 - The alternating voltage is an example of





An analogue waveform

249 - The angular position of cells remains the same for a sample of a crystal. This property is called





The external symmetry of form

250 - The band theory of solids explains satisfactorily the nature of





All of the above

251 - The bats can fly in the dark because





They generate ultrasonic sound waves

252 - The bending of light when it passes around a corner or a slit is due to ________





Diffraction

253 - The blue colour of water in the sea is due to





Absorption of other colours except blue by water molecules

254 - The bombardment of nitrogen with ?-particles will produce





Proton

255 - The breaking of crystals along definite direction is called





Cleavage

256 - The bulk properties of materials such as their mode of fracture can be related to their





Microstructure

257 - The centre of gravity of a sprinter during the race lies





Ahead of his feet

258 - The characteristic invalid for heat radiation is that it travels :





With the speed of light

259 - The characteristic X-rays spectrum is due to





The bombardment of target by electrons.

260 - The charged particle enters the uniform magnetic field in such a way that its initial velocity is not perpendicular to the field the orbit will be





helix

261 - The colour of the ocean appears to be blue because the sunlight falling on it is





Scattered

262 - The curie temperature is that at which





Ferromagnetic becomes paramagnetic

263 - The current through a metallic conductor is due to the motion of





free electrons

264 - The deflection for 50 division of galvanometer is decreased to 25 divisions by shunt resistance of 12 ohm. Galvanometer resistance is





12 ohm

265 - The density of the liquid when heated





Decreases

266 - The device or circuit used for conversion of A . C .into D . C .is called





A rectifier

267 - The device used for conversion of D . C .to A . C .is called





Oscillator

268 - The device used for locating submerged objects under sea is.





Sonar

269 - The direction of propagation of an electromagnetic waves is





Perpendicular to both electric and magnetic field

270 - The effective way to increase the sensitivity of a moving coil galvanometer is to





use a very strong magnetic field

271 - The electric lines of force are





imaginary

272 - The electronic circuits which implement the various logic operations are called





Logic gates

273 - The electrons in conduction band are free to





Transport charge

274 - The emf induced in a coil by a changing magnetic flux may have unit as





kgm2s-1A-1

275 - The emf induced in a conductor of unit length moving with unit velocity at right angles to a magnetic field is equal to





Magnetic flux density

276 - The energy band occupied by the valence electrons is called





Valence band

277 - The energy radiated is directly proportional to fourth power of Kelvins temperature is





Stephens law.

278 - The especially designed semiconductor diodes used as indicator lamps in electronic circuits are





The light emitting diode

279 - The existence of Ether wind was experimentally rejected by





infinite

280 - The force per unit charge is know as





electric intensity

281 - The graphical representation of Ohms law is





straight line

282 - The Hooke's law is valid for





Only proportional region of the stress strain curve

283 - The linear momentum of an X-ray photon of wavelength 0.1A is





6.625x1023N-s

284 - The magnetic force experienced by a charge particle moving in a magnetic field will be minimum when it moves





parallel to the field

285 - The maximum safe limit dose for persons working in nuclear power station are





5 rem per week

286 - The metallic spheres A and B of radii 2m and 4m respectively carry the same charge 4 x 10 8





If the spheres are connected by a copper wire

287 - The metastable state for an atom in laser light is





10-3 sec

288 - The minimum charge on any object cannot be less than





1.6 x 10-19C

289 - The minimum wavelength of X-rays can further be reduced by





Increasing the potential difference between the cathode and the target.

290 - The minimum wavelength of X-rays produced by the bombardment of electrons on the screen of a television set where the accelerating potential is 2.0K V will be





6.2 x 10-10m

291 - The modulus of elasticity for mild steel is approximately equal to





210 kN/mm2

292 - The moment of inertia of a body does not depend upon





The angular speed of the body

293 - The most useful tracer is





C-14

294 - The name of the photon for quantum of light was proposed by





Einstein

295 - The net charge on n-type material is





Neutral

296 - The number of electrons in one coulomb charge is equal to





6.2 x 1018

297 - The only difference between construction of D . C generator and A . C generator is that of





commutator

298 - The operation of a transistor requires





None of the above

299 - The operational amplifier is





A high gain amplifier

300 - The out put voltage of a transformer is 3 times the input voltage then turns ratio will be





3

301 - The penetrating power of X-rays depends on their





frequency

302 - The phase angle between the voltage and the current in an AC circuit consisting of a resistance is





Zero

303 - The practical illustration of the phenomenon of mutual induction is





transformer

304 - The radiations emitted form hydrogen filled discharge tube show





line spectrum

305 - The ration stress to strain in youngs modulus of the material then tension is





Directly proportional to extension.

306 - The rectangular voltage is an example of





A digital waveform

307 - The relationship between Tesla and smaller unit Gauss of magnetic induction is given by





1T = 104 G

308 - The relativistic energy E is equivalent to relativistic mass given by





E/c2

309 - The resistance of a conductor at absolute zero (OK) is





zero almost

310 - The self-inductance of a solenoid is increased when a soft iron core is inserted into it. This is because the soft iron core





Improves the flux linkage between the turns of the coil

311 - The semiconductor diode can be used as a rectifier because _





It has low resistance to the current flow when forward biased & high resistance when reverse biased.

312 - The sensitivity of a galvanometer is given by





C/BAN

313 - The simplest type of rectification known as half wave rectification is obtained by





suppressing half wave of A . C supply by using diode

314 - The sounds having a frequency of 20 Hertz to 20,000 Hertz are known as





Audible sounds

315 - The specially designed semi-conductor diodes used as fast counters in electronic circuits are





Photo diodes

316 - The standard vector symbol for flux density is





"B"

317 - The tidal waves on sea is mainly due to





Gravitational Effect of Moon on Earth

318 - The time period of a pendulum when taken to the Moon would:





Increase

319 - The uncertainty in momentum & position is due to its





Property of matter and radiation.

320 - The unit of radioactivity curie is equal to





3.70 x 1010 disintegration per sec

321 - The value of resistivity for insulator is of the order of





108 ohm metre

322 - The value of the capacitance depends upon the





geometry of the capacitor

323 - The value of the steady current which when flowing through the same resistor produces heat at the same rate as the mean rate of heat produced by the alternating current is





r.m.s current

324 - The velocity of an oscillating charge as it moves to and fro along a wire is always





changing

325 - The velocity of laser light is





Equal to ordinary light.

326 - The working of transistor as amplifier is similar to





Triode vacuum tube

327 - There are three bulbs of 60W 100W and 200W which bulb has thickest filament.





200W

328 - Thermions are





electrons

329 - Thermocouples convert





heat energy into electrical energy

330 - Three bulbs are rating 40W 60W and 100W designed to work on 220V mains. Which bulb will burn most brightly if they are connected in series across 220 V mains?





40 W bulb

331 - Three capacitors C1 C2 and C3 are connected in parallel as in the Fig. The equivalent capacitance will be





8 Degree F

332 - Three equal resistors connected in series with a source of e m f together dissipate 10 W of power each. What will be the power dissipated if the same resistors are connected in parallel across the same source of e m f?





90W

333 - Tick the correct statement





all the above statements are true

334 - Tick the correct statement





all the above

335 - Tick the correct statement





all of above

336 - Tick the correct statement





moderators slow down the neutrons

337 - Tick the only wrong statement.





an electrically neutral body is repelled both positively and negatively charged bodies

338 - Tick the right statement.





all of the above

339 - To find the r.m.s value of an alternating current mathematically we need to have





Square root of mean value of I2

340 - To obtain a p-type semi-conductor Si Crystal must be doped with foreign atoms whose valency is





3

341 - To obtain an n-type semiconductor germanium crystal it must be doped with foreign atoms whose valency is





5

342 - Total number of series in hydrogen spectrum is





five

343 - Transformer works on the principle of





Mutual induction

344 - Transuranic elements have atomic number





greater than 92

345 - Two charges are placed at a certain distance. If the magnitude of each charge is doubled the force will become





4 times of its original value

346 - Two identical coaxial circular loops carry equal currents in the same direction. If the loops approach each other the current in





Each decreases

347 - Two oppositely charged balls A and B attract third conducting ball C when placed near them turn by turn. Then ball C must be





electrically neutral

348 - Two parallel wires carrying currents in the opposite directions





repel each other

349 - Two similar charges each of one coulomb placed in air one meter apart repel each other with a force





9 x 109N

350 - UV radiation can be produced by





Electron excitation in the gas.

351 - Value of ?r for various dielectrics is always





larger than unit

352 - Various types of cancer are treated by





cobalt-60

353 - Very weak magnetic fields are detected by





Squids

354 - Visible light has a higher frequency than





Radio waves

355 - Wave-like characteristic of electron is demonstrated by





Diffraction by crystalline solids.

356 - Waves emitted from the antenna are





Electromagnetic waves

357 - Weber is the unit of





magnetic flux

358 - What happens to a liquid, when the vapour pressure equals the atmospheric pressure?





The liquid boils

359 - What is the self inductance of a coil in which an induced emf of 2V is set up when the current changes at the rate of 4 As-1?





0.5H

360 - What is the SI unit of modulus of elasticity of substance?





Nm-2

361 - What is the value of the current in a wire of 10cm long at the right angle to a uniform magnetic field of 0.5 Weber/m2 when the force acting on the wire is 5N?





100A

362 - When a body falls from an aeroplane, there is increase in its





Acceleration

363 - When a particle of charge q and mass m enters into a uniform magnetic field B moving with a velocity v perpendicular to the direction for the field it describes a circular path of radius





R=mV/qB

364 - When a pure inductor of inductance L and a pure capacitor of capacitance C are connected in parallel to a sinusoidal potential difference V the potential difference across both L & C will be





Same

365 - When an electron moving with a uniform speed in a vacuum enters a magnetic field in a direction perpendicular to the field the subsequent path of the electron is





a circle in a plane perpendicular to the field

366 - When same current passes for same time through a thick and thin wire





more heat is produced in thin wire

367 - When the coil of the galvanometer is in equilibrium then the deflecting couple is





equal to the restoring couple

368 - When the motor is at its maximum speed then back emf will be





Maximum

369 - When we excite some atoms by heat collision or electrical discharge they will





radiate electromagnetic energy of discrete characteristic wavelength

370 - When X-rays are passed through successive aluminum sheets what happens to their thickness?





it remains same

371 - Which of the following branch of Physics deal with study of Atomic Nuclei?





Nuclear Physics

372 - Which of the following has the highest entropy?





Hydrogen

373 - Which of the following never occurs singly in nature?





Force

374 - Which of the following statements is true when we see ''rainbow' ?





The Sun remains behind us and we face raindrops

375 - Which of the following substances posses the highest elasticity?





Steel

376 - Which of the following uses electric energy and does not convert it into any other form?





transformer

377 - Which of the following works on torque on the current carrying conductor placed in magnetic field.





all of the above

378 - Which of these branches of Physics deal with heat and temperature and their relation to energy and work?





Thermodynamics

379 - Which one has the greatest energy gap ?





Non metals

380 - Which one is the best material for making connecting wires?





copper

381 - Which one of following band is completely filled in case of conductors?





Conduction band

382 - Which one of following postulate is in accordance with the Rutherfords model?





continuous spectra for atoms

383 - Which one of the following bulbs has the least resistance?





300 watt

384 - Which one of the following devices does not function like an electric motor?





Transformer

385 - Which one of the following functions like a motor?





all of above

386 - Which one of the following has the greatest energy gap?





insulator

387 - Which one of the following is not a donor impurity?





aluminium

388 - Which one of the following is not an electromechanical instrument?





AC transformer and DC generator

389 - Which one of the following material is most suitable for making core of an electromagnet?





soft iron

390 - Which one of the following materials is useful for making bulb filaments?





constantan

391 - Which one of the following methods would be able to increase the sensitivity of a moving coil galvanometer ?





use spiral springs whose force constant is small

392 - Which one of the following physical quantities does not have the dimensions of force per unit area?





Strain

393 - Which one of the following radiations has the strongest photon?





?-rays

394 - Which one of the following ray has minimum wavelength?





Gamma ray

395 - While measuring the unknown resistance the help of slide wire bridge a greatest accuracy can be achieved when





the balance point is close to the middle of the wire

396 - Who enunciated the laws of planetary motion?





Johannes Kepler

397 - Why should a resistance be introduced in a circuit in series deliberately?





to decrease current

398 - With increase in temperature the electrical conductivity of intrinsic semi conductor





Increases

399 - X-ray are





high energy photons

400 - X-rays are diffracted by a crystal but not by a diffraction grating because





The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal

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