Current electricity

31. In a circuit a 33 Ohm resistor carries a current of 2

The voltage across the resistor is A. 33 V
66 V
80 V
132 V

Detailed SolutionIn a circuit a 33 Ohm resistor carries a current of 2

32. Which of the following can have negative temperature coefficient?

Compounds of silver
Liquid metals
Metallic alloys
Electrolytes

Detailed SolutionWhich of the following can have negative temperature coefficient?

33. Out of the following which is not a poor conductor?

Cast iron
Copper
Carbon
Tungsten

Detailed SolutionOut of the following which is not a poor conductor?

34. The resistance of a copper wire 200 m long is 21 $$\Omega .$$ If its thickness (diameter) is 0.44 mm, its specific resistance is around

1.2 x 10-8 $$Omega $$-m
1.4 x 10-8 $$Omega $$-m
1.6 x 10-8 $$Omega $$-m
1.8 x 10-8 $$Omega $$-m

Detailed SolutionThe resistance of a copper wire 200 m long is 21 $$\Omega .$$ If its thickness (diameter) is 0.44 mm, its specific resistance is around

35. Whether circuit may be AC. or D.C. one, following is most effective in reducing the magnitude of the current.

Reactor
Capacitor
or
Resistor

Detailed SolutionWhether circuit may be AC. or D.C. one, following is most effective in reducing the magnitude of the current.

36. Resistance of a tungsten lamp as applied voltage increases

Decreases
Increases
Remains same
None of the above

Detailed SolutionResistance of a tungsten lamp as applied voltage increases

37. The ratio of mass of proton to that of electron is nearly

1840
1480
30
4

Detailed SolutionThe ratio of mass of proton to that of electron is nearly

38. In a lamp load when more than one lamp are switched on the total resistance of the load

Increases
Decreases
Remains same
None of the above

Detailed SolutionIn a lamp load when more than one lamp are switched on the total resistance of the load

39. Out of the following which is an insulating material?

Copper
Gold
Silver
Paper

Detailed SolutionOut of the following which is an insulating material?

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