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Q1. | In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will |

A. | increase [Wrong Answer] |

B. | decrease [Correct Answer] |

C. | remain the same [Wrong Answer] |

D. | initially increase and then decrease [Wrong Answer] |

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Explanation:-
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**Also Read Similar Questions Below :**

⇒ Mutually inductance between two magnetically-coupled coils depends on

permeability of the core

the number of their turns

cross-sectional area of their common core

all of the above

⇒ 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

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

Inductance

Condenser

Variable resistor

Resistance

⇒ 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

⇒ A coil with negligible resistance has 50 V across it with 10 mA. The inductive reactance is

50 ohms

500 ohms

1000 ohms

5000 ohms

⇒ An averaVoltage 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

20 Wb

2 Wb

0.2 Wb

0.02 Wb

⇒ 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

⇒ 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

⇒ In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will

increase

decrease

remain the same

initially increase and then decrease

⇒ 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

⇒ In case of an inductance, current is proportional to

voltage across the inductance

magnetic field

both (a) and (b)

neither (a) nor (b)

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

Faraday

Lenz

Newton

Coulomb

⇒ 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

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

300 µH

600 µH

150 µH

75 µH

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

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charge

enery

induced e.m.f.

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

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350 mH

250 mH

150 mH

⇒ The property of coil by which a counter e.m.f. is induced in it when the current through the coil chatiges is known as

self-inductance

mutual inductance

series aiding inductace

capacitance

⇒ 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

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

Resistance only

Inductance only

Capacitance only

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⇒ The core of a coil has a length of 200 mm. The inductance of coil is 6 mH. If the core length is doubled, all other quantities, remaining the same, the inductance will be

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⇒ Which of the following circuit elements will oppose the change in circuit current?

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⇒ Current changing from 8 A to 12 A in one second induced 20 volts in a coil. The value of inductance is

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5 H

10 H

⇒ 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

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

NI/Φ

NΦ/I

NI

^{2}/Φ

NΦ/I

^{2}

⇒ 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

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

Henry

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Volt second per ampere

All of the above

⇒ Air-core coils are practically free from

hysteresis losses

eddy current losses

both (a) and (b)

none of the above

⇒ 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 is unit of inductance?

Ohm

Henry

Ampere turns

Webers/metre