The polarity of the induced voltage can be determined by using the left-hand generator rule

Related Mcqs:

1. A 500 turns solenoid develops an average induced voltage of 60 V. Over what time interval must a flux change of 0.06 Wb occur to produce such a voltage ?

   A. 0.01 s
   B. 0.1 s
   C. 0.5 s
   D. 5 s

2. The only difference between construction of D.C generator and A.C generator is that of_______________?

   A. carbon brushes
   B. coil
   C. commutator
   D. magnetic field

3. If current in a conductor increases then according to Lenz’s law self-induced voltage will____________?

   A. aid the increasing current
   B. tend to decrease the amount of cur-rent
   C. produce current opposite to the in-creasing current
   D. aid the applied voltage

4. An average voltage of 10 V is induced in a 250 turns solenoid as a result of a change in flux which occurs in 0.5 second. The total flux change is____________?

   A. 20 Wb
   B. 2 Wb
   C. 0.2 Wb
   D. 0.02 Wb

5. A coil is wound on iron core which carries current I. The self-induced voltage in the coil is not affected by________________?

   A. variation in coil current
   B. variation in voltage to the coil
   C. change of number of turns of coil
   D. the resistance of magnetic path

6. The out put voltage of a transformer is 3 times the input voltage then turns ratio will be________________?

   A. 3-Jan
   B. 3
   C. 1
   D. 6

7. The property of coil by which a counter e.m.f. is induced in it when the current through the coil changes is known as__________?

   A. self-inductance
   B. mutual inductance
   C. series aiding inductance
   D. capacitance

8. 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

9. emf induced in a circuit according to Faradays law depends on the_____________?

   A. maximum magnetic flux
   B. rate of change of magnetic flux
   C. change in magnetic flux
   D. initial magnetic flux

10. 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