Current electricity

31. A glass rod when rubbed with silk cloth is charged because

It takes in proton
Its atoms are removed
It gives away electrons
It gives away positive charge

Detailed SolutionA glass rod when rubbed with silk cloth is charged because

32. The insulation on a current carrying conductor is provided

To prevent leakage of current
To prevent shock
Both of above factors
None of above factors

Detailed SolutionThe insulation on a current carrying conductor is provided

33. International ohm is defined in terms of the resistance of

A column of mercury
A cube of carbon
A cube of copper
The unit length of wire

Detailed SolutionInternational ohm is defined in terms of the resistance of

34. A light bulb draws 300 mA when the voltage across it is 240 V. The resistance of the light bulb is

400 Ohms
600 Ohms
800 Ohms
1000 Ohms

Detailed SolutionA light bulb draws 300 mA when the voltage across it is 240 V. The resistance of the light bulb is

35. Which of the following materials has the least resistivity ?

Zinc
Lead
Mercury
Copper

Detailed SolutionWhich of the following materials has the least resistivity ?

36. Which of the following quantities remain the same in all parts of a series circuit?

Voltage
Current
Power
Resistance

Detailed SolutionWhich of the following quantities remain the same in all parts of a series circuit?

37. In an electric kettle water boils in 10 m minutes. It is required to boil the boiler in 15 minutes, using same supply mains

Length of heating element should be decreased
Length of heating element should be increased
Length of heating element has no effect on heating if water
None of the above

Detailed SolutionIn an electric kettle water boils in 10 m minutes. It is required to boil the boiler in 15 minutes, using same supply mains

38. With rise in temperature the resistance of semiconductors

Decreases
Increases
First increases and then decreases
Remains constant

Detailed SolutionWith rise in temperature the resistance of semiconductors

39. A current of 16 amperes divides between two branches in parallel of resistances 8 ohms and 12 ohms respectively. The current in each branch is

6.4 A, 6.9 A
6.4 A, 9.6 A
4.6 A, 6.9 A
4.6 A, 9.6 A

Detailed SolutionA current of 16 amperes divides between two branches in parallel of resistances 8 ohms and 12 ohms respectively. The current in each branch is

40. In a series circuit with unequal resistances

The highest resistance has the most of the current through it
The lowest resistance has the highest voltage drop
The lowest resistance has the highest current
The highest resistance has the highest voltage drop

Detailed SolutionIn a series circuit with unequal resistances

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