Study mode · no timer

Electromagnetic Induction

Study 85 Electrical Engineering MCQs with correct answers and explanations.

Answers and explanations are always visible Take this test

51Electrical EngineeringMedium

A coil induces 350 mV when the current changes at the rate of 1 A/s. The value of inductance is________?

A150 mH

B3500 mH

C250 mH

D350 mH

Correct answer

D. 350 mH

Explanation

The correct answer is 350 mH.

52Electrical EngineeringMedium

Power loss in actual transformer is due to________?

AEddy currents and magnetic hysterias

BSoft iron core

CBack emf

DSmall output

Correct answer

A. Eddy currents and magnetic hysterias

Explanation

The correct answer is Eddy currents and magnetic hysterias.

53Electrical EngineeringMedium

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________?

AA torque about vertical axis

BAn upward force along the axis

CA torque about horizontal axis

DNo resultant force

Correct answer

D. No resultant force

Explanation

The correct answer is No resultant force.

54Electrical EngineeringMedium

The alternating current has frequency of 106 Hz in such a way that time period for completion of cycle is________?

A1.5Hzs

B1sec

C106sec

D1Hzs

Correct answer

D. 1Hzs

Explanation

The correct answer is 1Hzs.

55Electrical EngineeringMedium

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

Amagnetic field

Bcoil

Ccommutator

Dcarbon brushes

Correct answer

C. commutator

Explanation

The correct answer is commutator.

56Electrical EngineeringMedium

Non inductive resistances are used in decreasing________?

AMutual inductance

BHeating effect

CSelf inductance

DMagnetic fields

Correct answer

C. Self inductance

Explanation

The correct answer is Self inductance.

57Electrical EngineeringMedium

The law that the induced e.m.f. and current always oppose the cause producing them is due to________?

ANewton

BFaraday

CLenz

DCoulomb

Correct answer

C. Lenz

Explanation

The correct answer is Lenz.

58Electrical EngineeringMedium

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

Aproduce current opposite to the in-creasing current

Btend to decrease the amount of cur-rent

Caid the applied voltage

Daid the increasing current

Correct answer

A. produce current opposite to the in-creasing current

Explanation

The correct answer is produce current opposite to the in-creasing current.

59Electrical EngineeringMedium

The direction of induced e.m.f. can be found by________?

AFleming’s right hand rule

BLenz’s law

CKirchhoff s voltage law

DLaplace’s law

Correct answer

B. Lenz’s law

Explanation

The correct answer is Lenz’s law.

60Electrical EngineeringMedium

Which of the following is not a unit of inductance?

AVolt second per ampere

BAll of the above

CHenry

DCoulomb/volt ampere

Correct answer

D. Coulomb/volt ampere

Explanation

The correct answer is Coulomb/volt ampere.

51Electrical EngineeringMedium

A coil induces 350 mV when the current changes at the rate of 1 A/s. The value of inductance is________?

A150 mH

B3500 mH

C250 mH

D350 mH

Correct answer

D. 350 mH

Explanation

The correct answer is 350 mH.

52Electrical EngineeringMedium

Power loss in actual transformer is due to________?

AEddy currents and magnetic hysterias

BSoft iron core

CBack emf

DSmall output

Correct answer

A. Eddy currents and magnetic hysterias

Explanation

The correct answer is Eddy currents and magnetic hysterias.

53Electrical EngineeringMedium

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________?

AA torque about vertical axis

BAn upward force along the axis

CA torque about horizontal axis

DNo resultant force

Correct answer

D. No resultant force

Explanation

The correct answer is No resultant force.

54Electrical EngineeringMedium

The alternating current has frequency of 106 Hz in such a way that time period for completion of cycle is________?

A1.5Hzs

B1sec

C106sec

D1Hzs

Correct answer

D. 1Hzs

Explanation

The correct answer is 1Hzs.

55Electrical EngineeringMedium

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

Amagnetic field

Bcoil

Ccommutator

Dcarbon brushes

Correct answer

C. commutator

Explanation

The correct answer is commutator.

56Electrical EngineeringMedium

Non inductive resistances are used in decreasing________?

AMutual inductance

BHeating effect

CSelf inductance

DMagnetic fields

Correct answer

C. Self inductance

Explanation

The correct answer is Self inductance.

57Electrical EngineeringMedium

The law that the induced e.m.f. and current always oppose the cause producing them is due to________?

ANewton

BFaraday

CLenz

DCoulomb

Correct answer

C. Lenz

Explanation

The correct answer is Lenz.

58Electrical EngineeringMedium

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

Aproduce current opposite to the in-creasing current

Btend to decrease the amount of cur-rent

Caid the applied voltage

Daid the increasing current

Correct answer

A. produce current opposite to the in-creasing current

Explanation

The correct answer is produce current opposite to the in-creasing current.

59Electrical EngineeringMedium

The direction of induced e.m.f. can be found by________?

AFleming’s right hand rule

BLenz’s law

CKirchhoff s voltage law

DLaplace’s law

Correct answer

B. Lenz’s law

Explanation

The correct answer is Lenz’s law.

60Electrical EngineeringMedium

Which of the following is not a unit of inductance?

AVolt second per ampere

BAll of the above

CHenry

DCoulomb/volt ampere

Correct answer

D. Coulomb/volt ampere

Explanation

The correct answer is Coulomb/volt ampere.