Users Also Read

MCQ's Search Engine

Electrical Engineering

Mechanical Engineering

Civil Engineering

Automobile Engineering

Chemical Engineering

Computer Engineering

Electronics Engineering

Medical Science Engg

Q1. | Two coils have inductances of 8 mH and 18 mH and a co-efficient of coupling of 0.5. If the two coils are connected in series aiding, the total inductance will be |

A. | 32 mH [Wrong Answer] |

B. | 38 mH [Correct Answer] |

C. | 40 mH [Wrong Answer] |

D. | 48 mH [Wrong Answer] |

View Answer
Explanation:-
Answer : BDiscuss it below :Anupam Ghosh Said on 2020-01-11 03:34:45L=L1+L2+M =8+18+2×6=38 Mohsin Said on 2016-11-06 09:47:04Total Inductance =L1+L2+2M M= k*sq.rt(L1*L2) !! OOPS Login [Click here] is required to post your answer/resultHelp other students, write article, leave your comments |

**Also Read Similar Questions Below :**

⇒ Ifcurrentin a conductor increases then according to Lenz's law self-induced voltage will

aid the increasing current

tend to decrease the amount of current

produce current opposite to the increasing current

aid tite applied voltage

⇒ Air-core coils are practically free from

hysteresis losses

eddy current losses

both (a) and (b)

none of the above

⇒ The co-efficient of coupling between two air core coils depends on

self-inductance of two coils only

mutual inductance between two coils only

mutual inductance and self inductance of two coils

none of the above

⇒ The self inductances of two coils are 8 mH and 18 mH If the co-efficients of coupling is 0.5, the mutual inductance of the coils is

4 mH

5 mH

6 mH

12 mH

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

Faraday

Lenz

Newton

Coulomb

⇒ 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

50 N

120 N

240 N

480 N

⇒ In case all the flux from the current in coil 1 links with coil 2, the co-efficient of coupling will be

2.0

1.0

0.5

zero

⇒ An open coil has

zero resistance and inductance

infinite resistance and zero inductance

infinite resistance and normal inductance

zero resistance and high inductance

⇒ Two coils have inductances of 8 mH and 18 mH and a co-efficient of coupling of 0.5. If the two coils are connected in series aiding, the total inductance will be

32 mH

38 mH

40 mH

48 mH

⇒ A coil is wound on iron core which carries current I. The self induced voltage in the coil is not affected by

variation in coil current

variation in voltage to the coil

change of number of turns of coil

the resistance of magnetic path

⇒ Two 300 µH coils in series without mutual coupling have a total inductance of

300 µH

600 µH

150 µH

75 µH

⇒ The magnitude of the induced e.m.f. in a conductor depends on the

flux density of the magnetic field

amount of flux cut

amount of flux linkages

rate of change of flux-linkages

⇒ 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?

0.01 s

0.1 s

0.5 s

5 s

⇒ Which of the following statements is cotrect ?

The inductance of the coil carrying a constant D.C. current will change the current into pulses

The inductance of the coil carrying a constant D.C. current will increase the current

The inductance of the coil carrying a constant D.C. current will not affect the current

The inductance of the coil carrying a constant D.C. current will decrease the current

⇒ For a purely inductive circuit which of the following is true ?

Apparent power is zero

Relative power is zero

Actual power of the circuit is zero

Any capacitance even if present in the circuit will not be charged

⇒ A laminated iron core has reduced eddy-current losses because

more wire can he used with less D.C. resistance in coil

the laminations are insulated from each other

the magnetic flux is concentrated in the air gap of the core

the laminations are stacked vertically

⇒ Two coils have self-inductances of 10 H and 2 H, the mutual inductance being zero. If the two coils are connected in series, the total inductance will be

6 H

8 H

12 H

24 H

⇒ Which of the following circuit element stores energy in the electromagnetic field?

Inductance

Condenser

Variable resistor

Resistance

⇒ Which of the following is not a unit of inductance?

Henry

Coulomb/volt ampere

Volt second per ampere

All of the above

⇒ In case of an inductance, current is proportional to

voltage across the inductance

magnetic field

both (a) and (b)

neither (a) nor (b)

⇒ An e.m.f. of 16 volts is induced in a coil of inductance 4 H. The rate of change of current must be

64 A/s

32 A/s

16 A/s

4 A/s

⇒ The inductance df a coil will increase under all the following conditions except

when more length for the same number of turns is provided

when the number of turns of the coil increase

when more area for each turn is provided

when permeability of the core increases

⇒ As per Faraday's laws of electromagnetic induction, an e.m.f. is induced in a conductor whenever it

lies perpendicular to the magnetic flux

lies in a magnetic field

cuts magnetic flux

moves parallel to the direction of the magnetic field

⇒ Which of the following inductor will have the least eddy current losses?

Air core

Laminated iron core

Iron core

Powdered iron core

⇒ Which circuit element(s) will oppose the change in circuit current?

Resistance only

Inductance only

Capacitance only

Inductance and capacitance

⇒ Lenz's law is a consecluence of the law of conservation of

induced current

charge

enery

induced e.m.f.

⇒ A conductor 2 metres long moves at right angles to a magnetic field of flux densit 1 tesla with a velocity of 12.5 m/s. The induced e.m.f. in the conductor will be

10 V

15 V

25 V

50 V

⇒ The direction of induced e.m.f. can be found by

Laplace's law

Lenz's law

Fleming's right hand rule

Kirchhoffs voltage law

⇒ The co-efficient of self-inductance for a coil is given as

NI/Φ

NΦ/I

NI

^{2}/Φ

NΦ/I

^{2}

⇒ Higher the self-inductance of a coil,

lesser its weher-turns

lower the e.m.f. induced

greater the flux produced by it

longer the dela' in establishing steady current through it