Description : The practical application of electrostatic is: (a) Photocopier (b) X-rays machines (c) Laser (d) All of above 42. The electric field lines emerge from the charges in: (a) Three dimensions (b) Two dimensions (c) One dimension (d) All of above
Last Answer : (a) Photocopier
Description : The electric force between two charges placed in air is 2 Newton. When placed in a medium of ∈r = 80, the force reduced to: (a) 0.029 N (b) 0.025 N (c) 0.03 N (d) 0.04 N
Last Answer : (b) 0.025 N
Description : The electrostatic force of repulsion between two electrons at 1 metre is: (a) 9 × 109 N (b) 1.44 × 10−9 N (c) 2.30 × 10−28 N (d) 1 N
Last Answer : (c) 2.30 × 10−28 N
Description : Resistance of an ideal insulator is a. Infinite b. Zero c. Finite d. depends upon nature
Last Answer : a. Infinite
Description : In case of two identical charges placed at certain distance, the electric lines of force are: (a) Curved (b) Straight lines (c) Both (a) and (b) (d) None of these
Last Answer : a) Curved
Description : A doped semiconductor is called : a) Extrinsic b) Intrinsic c) Insulator d) Conductor
Last Answer : b) Intrinsic
Description : Pure semiconductors silicon and germanium are a) Extrinsic b) Intrinsic c) Insulator d) Diodes
Description : Due to self-inductance, the coil wires are known as: a. Insulator b. Conductor c. Inductor d. Semi-conductor
Last Answer : c. Inductor
Description : A wire having very high value of conductance is said to be a. very good conductor b. moderately good conductor c. an insulator d. None
Last Answer : a. very good conductor
Description : The force in a medium of relative permitivity ∈r is given by: (a) F′ =F (b) F′ =∈r ∈ F r (c) F′ = ∈r . F (d) F′ =F ∈ ∈
Last Answer : (a) F′ =F
Description : A magnetic field exists around (a) iron (b) copper (c) aluminium (d) moving charges
Last Answer : (d) moving charges
Description : The conventional current is due to the flow of a. atoms and molecules b. positive charges c. negative charges d. both b and c
Last Answer : b. positive charges
Description : In liquids and gases the current is due to the motion a. negative charges b. positive charges c. both negative and positive charges d. neutral particles
Last Answer : c. both negative and positive charges
Description : The electric field exist around: (a) Charges (b) On the left side (c) At the –ve charge (d) At the +ve charge
Last Answer : (a) Charges
Description : The space around the charge within which other charges are influenced by it is called: (a) Electric field (b) Magnetic field (c) Electric flux (d) Electric intensity
Last Answer : a) Electric field
Description : Which of the following statement is correct: (a) Similar charges attract each other (b) Similar charges attract and repel each other (c) Similar charges repel each other (d) Similar charges neither attract nor repel 9. Metals are good conductors of electricity because they have:
Last Answer : (c) Similar charges repel each other
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 : 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 : 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 : The electrostatic energy in an electric field does not depend on which of the following? a) Magnitude of charges b) Permittivity c) Applied electric field d) Flux lines
Last Answer : c) Applied electric field
Description : Has the per capita income increased or decreased from 1980 to 2009 ___. A. increased. B. decreased. C. medium. D. narrow.
Last Answer : C. medium.
Description : The _____ socialism seems to fall between capitalism and communism ____. A. increased. B. decreased. C. lowlevel. D. medium.
Last Answer : A. increased.
Description : Which of the following properties distinguish a material as conductor, insulator and semiconductor? a) Free electron charges b) Fermi level after doping c) Energy band gap d) Electron density
Last Answer : c) Energy band gap
Description : Electromagneticwaves are refractedwhen they a. pass into a medium of different dielectric constant b. are polarized at right angles to the direction of propagation c. encounter a perfectly conducting plane d. pass through a small slot in a conducting plane
Last Answer : a. pass into a medium of different dielectric constant
Description : .In electromagneticwaves,polarization a. is caused by reflection b.isdue to the transversenature ofthewaves c. results from the longitudinal nature of the waves d. is always vertical in an isotropic medium
Last Answer : b.isdue to the transversenature ofthewaves
Description : The unit of absolute permittivity of a medium is
Last Answer : Farad/ metre
Description : Which one of the following waves requires a material medium for their propagation? a) Light waves b) X– rays c) -rays d) Sound waves
Last Answer : d) Sound waves
Description : Conductivity of semi conductor is increased by: a) Decrease of temperature b) By keeping temperature constant c) Increase of temperature d) none of above
Last Answer : d) none of above
Description : The induced current can be increased by: a. Using strong magnetic field b. moving loop faster c. Replacing loop by coil d. all of above
Last Answer : d. all of above
Description : The number of revolutions through which a pulley will rotate from rest if its angular acceleration is increased uniformly from zero to 12 rad per sec2 during 4 sec and then uniformly decreased to 0 rad per sec2 during the next 3 sec would be a.46.4 b.26.74 c.11.6 d.3.2 e.17.7
Last Answer : b. 26.74
Description : Momentum of two objects moving with same speed but in opposite direction upon collision is A. increased B. decreased C. is zero D. is infinite
Last Answer : is zero
Description : For a symmetrical two hinged parabolic arch, if one of the supports settles horizontally, then the horizontal thrust (A) Is increased (B) Is decreased (C) Remains unchanged (D) Becomes zero
Last Answer : (B) Is decreased
Description : For a two-hinged arch, if one of the supports settles down vertically, then the horizontal thrust (A) Is increased (B) Is decreased (C) Remains unchanged (D) Becomes zero
Last Answer : (C) Remains unchanged
Description : To ensure uniform pressure distribution, the thickness of the foundation, is A) Kept uniform throughout (B) Increased gradually towards the edge (C) Decreased gradually towards the edge (D) Kept zero at the edge
Last Answer : Answer: Option C
Description : The efficiency of Diesel cycle approaches to Otto cycle efficiency when A. cut-off is increased B. cut-off is decreased C. cut-off is zero D. cut-off is constant
Last Answer : Answer: C
Description : In a ferromagnetic material the state of flux density is as follows when external magnetic field is applied to it. (A) Increased (B) Decreased (C) Remains unchanged (D) Becomes 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 : Rest mass of the photon is a) Infinite b) Zero c) Very small d) 1.67 10-27 Kg
Last Answer : b) Zero
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 : When a motor is just started, back emf is almost ______: a. Infinite b. zero c. minimum d. maximum
Last Answer : d. maximum
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 : The magnetic field is _________ inside a solenoid a) Zero b) uniform c) non-uniform d) infinite
Last Answer : b) uniform
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