Description : If energy of incident photon is greater than the rest mass energy of electron positron pair, the surplus energy is shared by the pair as, a) Potential energy b) Thermal energy c) Electronic energy d) Kinetic energy
Last Answer : d) Kinetic energy
Description : If a material object moves with the speed of light ‘c’ its mass becomes a) equal to its rest mass b) Four times of its rest mass c) Double of its rest mass d) Infinite
Last Answer : d) Infinite
Description : When a motor is just started, back emf is almost ______: a. Infinite b. zero c. minimum d. maximum
Last Answer : d. maximum
Description : The magnetic field is _________ inside a solenoid a) Zero b) uniform c) non-uniform d) infinite
Last Answer : b) uniform
Description : Terminal potential difference of a battery is greater than its emf when a. the internal resistance of battery is infinite b. the internal resistance of battery is zero c. the battery is charged d. the battery is discharged
Last Answer : c. the battery is charged
Description : The resistance of a conductor at absolute zero (OK) is a. zero almost b. infinite almost c. May increase or decrease d. None
Last Answer : zero almost
Description : Resistance of an ideal insulator is a. Infinite b. Zero c. Finite d. depends upon nature
Last Answer : a. Infinite
Description : The phenomena of pair production occurs only when the energy of incident photon is least equal a) 10.2 MeV b) 1.02 MeV c) 1.02 eV d) 0.102 MeV
Last Answer : b) 1.02 MeV
Description : Whichofthe followingterms describesthe reason thatlightisrefractedat different angles? a. Photon energy changes with wavelength b. Light is refracted as a function of surface smoothness c. The angle is determined partly by a and b d. The angle is determined by the index of the materials
Last Answer : d. The angle is determined by the index of the materials
Description : The emission in which the atom emits a photon of energy hf = E2 – E1 , in any arbitrary direction is a) Spontaneous emission b) stimulated emission c) induced emission d) both a & c
Last Answer : d) both a & c
Description : The incident photon absorbed by an atom in the ground state E1, thereby leaving the atom in the excited state E2 , is a) spontaneous absorption b) stimulated absorption c) induced absorption d) both b & c
Last Answer : d) both b & c
Description : By the transition of inner shell electrons in heavy atoms, high energy photons are emitted which are a) gamma rays b) X-rays c) radio waves d) photon rays
Last Answer : b) X-rays
Description : Which one of the following radiations has the most energetic photon? a) T.V. waves b) Micro waves c) X-rays d) - rays
Last Answer : d) - rays
Description : 0.001 Kg mass will be equivalent to a) 2.50 Giga watt hour b) 25.00 giga watt hour c) 0.26 giga watt hour d) None of the above
Last Answer : b) 25.00 giga watt hour
Description : A ball of mass 1 kg moving with a velocity of 2 m/sec collides directly with a stationary ball of mass 2 kg. If the first ball comes to rest after the impact the velocity of second ball after impact will be a.1.5 m/sec b.0.5 m/sec c.Zero d.2 m/sec e.1.0 m/sec
Last Answer : e. 1.0 m/sec
Description : In penalty approach, rigid support is considered as a spring having stiffness. a.zero b.very small c.very large d.infinite
Last Answer : d.infinite
Description : A rod at rest appears to an observer just a mere point when he moves across it as speed, a) Equal to the speed of light b) Double the speed of light c) Three-fourth the speed of light d) None of the above
Last Answer : a) Equal to the speed of light
Description : Tick the wrong statement. a) Velocity of light is independent of the motion of the observer. b) Velocity of light in free space is the same in all directions. c) Velocity of light in free space is different in different directions. d) Absolute motion or absolute rest is meaningless to talk about
Last Answer : c) Velocity of light in free space is different in different directions
Description : A galvanometer in which the coil quickly comes to rest is called a ________ galvanometer a) Ballistic b) Mirror c) Astatic d) Dead beat
Last Answer : d) Dead beat
Description : The branch of physics which deals with the charges at rest: (a) Current electricity (b) Electromagnetism (c) Electrostatics (d) Nuclear physics
Last Answer : (c) Electrostatics
Description : The mass and energy equivalent to 1 a.m.u. respectively are - (1) 1.67 x 10−27 g, 9.30 MeV (2) 1.67 x 10−27kg, 930 MeV (3) 1.67 x 10−27kg, 1 MeV (4) 1.67 x 10−34 kg, 1 MeV
Last Answer : (2) 1.67 x 10−27kg, 930 MeV Explanation: The mass and energy equivalent to 1 a.m.u. respectively are 1.67 x 10−27kg, 930 MeV.
Description : A car having a mass of 1000 kg deflects its springs 4 cm under its load. Determine the natural frequency of the car in vertical direction. A 5 Hz B 4.67 Hz C 9.8 Hz D 2.49 Hz
Last Answer : D 2.49 Hz
Description : A car having a mass of 1000 kg deflects its springs 4 cm under its load. Determine the natural frequency of the car in vertical direction. A 5 HzB 4.67 Hz C 9.8 Hz D 2.49 Hz
Description : A car having a mass of 1000 kg deflects its springs 4 cm under its load. D Determine the natural frequency of the car in vertical direction. (A)5 Hz (B) 4.67 Hz (C) 9.8 Hz (D) 2.49 Hz
Last Answer : (D) 2.49 Hz
Description : Two masses, one of the 10kg and the other unknown, are placed on a scale in a region where g = 9.67 m/sec2 . The combined weight of these two masses is 174.06 N. Find the unknown mass in kg. a. 20 kg b. 19 kg c. 18 kg d. 17 kg formula: m=Fg k / g
Last Answer : 18 kg
Description : Thermistor with high negative temperature coefficient are very accurate for measuring low temperature especially near is a. 10 K b. 70K c. 200K d. 35K
Last Answer : c. 200K
Description : Mass of satellite orbiting Earth is A. considered B. irrelevant C. should be infinite D. should be zero
Last Answer : should be infinite
Description : A conductor of length L has current I passing through it, when it is placed parallel to a magnetic field. The force experienced by the conductor will be (a) zero (b) BLI (c) B2LI (d) BLI2
Last Answer : (a) zero
Description : Air gap has_______eluctance as compared to iron or steel path (a) little (b) lower (c) higher (d) zero
Last Answer : (b) lower
Description : Under ideal conditions, the collector current is (a) Equal to base current (b) Nearly equal to emitter current (c) Less than base current (d) always zero
Last Answer : (b) Nearly equal to emitter current
Description : The output from a full wave rectifier is (a) A pulsating uni-directional current (b) A DC voltage (c) Zero (d) An AC voltage
Last Answer : a) A pulsating uni-directional current
Description : In a half wave rectifier the rms value of AC component of the waves (a) Zero (b) Equal to DC value (c) More than DC value (d) Less than DC value
Last Answer : b) Equal to DC value
Description : If PN junction is forward biased its resistance is (a) Zero (b) Infinity (c) A few ohm (d) A few kilo ohms
Last Answer : c) A few ohm
Description : In the plane of AC generator coil is parallel to the field, then emf induced in coil is: a. maximum b. minimum c. zero d. intermediate
Last Answer : b. minimum
Description : In the plane of the A.C generator coil is perpendicular to the field, then induced emf in the coil is: a. Maximum b. minimum c. zero d. intermediate value
Description : If the motor is overloaded, then the magnitude of ‘back emf’” a. Increases b. Decreases c. Constant d. Becomes zero
Last Answer : Increases
Description : A wire loop is moved parallel to a uniform magnetic field. The induced emf in the loop: a. depends on the shape b. depends on area c. depends on nature of loop d. zero
Last Answer : d. zero
Description : If velocity of a conductor moving through a magnetic field ‘B’ is made zero, then Motional emf will be: a. –VBL b. –V/BL c. – BL/V d. zero
Last Answer : a. –VBL
Description : Work done by a uniform magnetic field in moving a charged particle in a circular path is a) qvB sin θ b) mg sin θ c) zero d) mg cos θ
Last Answer : Zero
Description : An electron moves with a velocity of 2 × 106 ms-1 in the direction of a uniform magnetic field of 0.8 Tesla. The force on electron is a) 8 N b) 2 N c) 4 N d) Zero
Last Answer : d) Zero
Description : In the following figure, the terminal potential is a. zero b. 2V c. 12V d. 36V
Last Answer : a. zero
Description : A wire of uniform area of cross-section A length L and resistance R is cut into two parts. Resistivity of each part a. remains the same b. is doubled c. is halved d. becomes zero
Last Answer : a. remains the same
Description : The number of electrons in one coulomb charge is equal to: (a) 6.2 × 1018 electrons (b) Zero electrons (c) 1.6 × 10−22 electrons (d) 6.2 × 1021 electrons
Last Answer : (a) 6.2 × 1018 electrons
Description : When the medium is insulator the electrostatic force between the charges is: (a) Decreased (b) Zero (c) Increased (d) None of above
Last Answer : (a) Decreased
Description : If charge stored on plates of capacitor is large, then capacitance will be A. small B. large C. zero D. infinite
Last Answer : large
Description : If the velocity of propagation in a certain medium is 200x106 m/s, what is its refractive index? A. 1.3 B. 1.5 C. 1.27 D. 0.67
Last Answer : B. 1.5
Description : A proton of mass `1.67xx10^(-27)` kg charge `1.6xx10^(-19) C` is projected in xy-plane with a speed of `2xx10^(6) m//s` at an angle of `60^(@)` to the
Last Answer : A proton of mass `1.67xx10^(-27)` kg charge `1.6xx10^(-19) C` is projected in xy-plane with a speed ... radius 0.14 m and time period `1.0xx10^(-7)s`
Description : A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure ofabout 67 kg/cm. The refrigerant used is (a) Ammonia (b) Carbon dioxide (c) Freon (d) Brine
Last Answer : Ans: b
Description : The section modulus of a rectangular light beam 25 metres long is 12.500 cm3 . The beam is simply supported at its ends and carries a longitudinal axial tensile load of 10 tonnes in addition to a point load of ... 13.33 kg/cm2 compressive (C) 26.67 kg/cm2 tensile (D) 26.67 kg/cm2 compressive
Last Answer : (C) 26.67 kg/cm2 tensile
Description : The relativistic energy ‘E’ is equivalent to relativistic mass given by a) Ec2 b) 2 c E c) c E d) E c
Last Answer : b) 2 c E