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

Related Mcqs:

1. A conductor 2 meters long moves at right angles to a magnetic field of flux density 1 tesla with a velocity of 12.5 m/s. The induced e.m.f. in the conductor will be____________?

   A. 10 V
   B. 15 V
   C. 25V
   D. 50V

2. 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_____________?

   A. Induced current
   B. Eddy current
   C. Back emf
   D. None of the above

3. 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_____________?

   A. 0 volt
   B. 3.125 volt
   C. 31.25 volt
   D. 0.03125 volt

4. A coil of wire is arranged with its plane perpendicular to a uniform magnetic field o flux density B. when the radius of the coil increases from r1 to r2 in time Δt then what is the emf induced in the coil ?

   A. ωB/r22-r12/Δt
   B. ωB(r2-r1)2/Δt
   C. ωB(r22-r12)/Δt
   D. ωB(r22+r12)/Δt

5. 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 = 4×10-5T). At maximum speed an emf of 96mV is induced across the wing tips. The maximum speed of the aeroplane is____________?

   A. 150msec-1
   B. 384msec-1
   C. 38.4msec-1
   D. 200msec-1

6. Find the force acting on a conductor 3m long carrying a current of 50 amperes at right angles to a magnetic field having a flux density of 0.67 tesla

   A. 100 N
   B. 400 N
   C. 600 N
   D. 1000 N

7. The emf induced in a coil by a changing magnetic flux may have unit as______________?

   A. ms-1A
   B. ms-2A-1
   C. kgms2A-1
   D. kgm2s-1A-1

8. A conductor carries 125 amperes of current under 60° to a magnetic field of 1.1 tesla. The force on the conductor will be nearly______________?

   A. 50 N
   B. 120 N
   C. 240 N
   D. 480 N

9. 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_____________?

   A. Retaintivity
   B. Permeability
   C. Flux
   D. Hysteresis

10. The resistance of a conductor of diameter d and length l is R Ω. If the diameter of the conductor is halved and its length is doubled, the resistance will be

    A. R Ω
    B. 2R Ω
    C. 4R Ω
    D. 8R Ω