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Q1. | An open coil has |

A. | zero resistance and inductance [Wrong Answer] |

B. | infinite resistance and zero inductance [Correct Answer] |

C. | infinite resistance and normal inductance [Wrong Answer] |

D. | zero resistance and high inductance [Wrong Answer] |

View Answer
Explanation:-
Answer : BDiscuss it below :!! OOPS Login [Click here] is required to post your answer/resultHelp other students, write article, leave your comments |

**Also Read Similar Questions Below :**

⇒ A crack in the magnetic path of an inductor will result in

unchanged inductance

increased inductance

zero inductance

reduced inductance

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

Faraday

Lenz

Newton

Coulomb

⇒ 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

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

Henry

Coulomb/volt ampere

Volt second per ampere

All of the above

⇒ 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

⇒ 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

⇒ 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

⇒ In case of an inductance, current is proportional to

voltage across the inductance

magnetic field

both (a) and (b)

neither (a) nor (b)

⇒ 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

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

induced current

charge

enery

induced e.m.f.

⇒ 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

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

NI/Φ

NΦ/I

NI

^{2}/Φ

NΦ/I

^{2}

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

Air core

Laminated iron core

Iron core

Powdered iron core

⇒ A 200 turn coil has an inductance of 12 mH. If the number of turns is increased to 400 turns, all other quantities (area, length etc.) remaining the same, the inductance will be

6 mH

14 mH

24 mH

48 mH

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

Capacitance

Inductance

Resistance

All of the above

⇒ 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

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

3500 mH

350 mH

250 mH

150 mH

⇒ Which of the following is unit of inductance?

Ohm

Henry

Ampere turns

Webers/metre

⇒ 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 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

⇒ 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

⇒ 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.

100 N

400 N

600 N

1000 N

⇒ Air-core coils are practically free from

hysteresis losses

eddy current losses

both (a) and (b)

none of the above

⇒ 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

⇒ 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

⇒ 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

⇒ 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

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

300 µH

600 µH

150 µH

75 µH