D.C Basic and network and electromagnetic theory. Part – 3

21. An electric iron drawing 9A from 120V supply mains is operated 20 minutes, the energy consumed is

A. 1080 W

B. 3 Ah

C. 0.6 kwh

D. 360 Wh

22. If three capacitors each of 50 microfarad are connected in parallel, the resultant capacitance will be:

A. 16.67 Micro farad

B. 100 Micro farad

C. 50 Micro farad

D. 150 Micro farad

23. There is a voltage drop of 100 volt across a resistance of 100 ohm. How much power will be consumed?

A. 100 Watt

B. 10 Watt

C. 1000 Watt

D. 1 Watt

24. An electric iron is marked as 230 V, 800 Watt. How many units of electrical energy are consumed if it is used for 10 hours?

A. 800

B. 8

C. 80

D. 8000

25. If the number of turns of a solenoid is doubled, its self inductance will be

A. Same as original

B. Double the original

C. Four times the original

D. Half the original

26. If the voltage across the combination remains constant, as we combine the resistors in parallel, the power consumption,

A. Remain the same

B. Decreases

C. Increases

D. May increase of decrease

27. Superposition theorem can be applied only to circuits having

A. Resistive elements

B. Passive elements

C. Linear bilateral elements

D. Non-linear elements

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

A. Flux density of the magnetic field

B. Amount of flux linkages

C. Rate of change of flux-linkages

D. Amount of flux cut

29. E.M.F can be induced in a circuit by

A. changing magnetic flux density

B. changing area of circuit

C. changing the angle

D. all of above

30. If current in a conductor increases then according to Lenz’s law self-induced voltage will

A. Tend to decrease the amount of current

B. Aid the applied voltage

C. Aid the increasing current

D. Produce current opposite to the increasing current