The thickness of insulation provided on the conductor depends on_____________?

A. the magnitude of voltage on the conductor
B. the magnitude of current flowing through it
C. both A. and (b)
D. none of the above

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

A. Voltage
B. Current
C. Power
D. Resistance

A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will__________

A. decrease
B. increase
C. remain same
D. heater will burn out

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

A. length of heating element should be decreased
B. length of heating element should be increased
C. length of heating element has no effect on heating if water
D. none of the above

An electric filament bulb can be worked from____________?

A. D. C. supply only
B. A. C. supply only
C. Battery supply only
D. All above

Resistance of a material always decreases if___________?

A. temperature of material is decreased
B. temperature of material is increased
C. number of free electrons available become more
D. none of the above is correct

If the efficiency of a machine is to be high, what should be low __________?

A. Input power
B. Losses
C. True component of power
D. kWh consumed

When electric current passes through a metallic conductor, its temperature rises. This is due to__________?

A. collisions between conduction electrons and atoms
B. the release of conduction electrons from parent atoms
C. mutual collisions between metal atoms
D. mutual collisions between conducting electrons

Two bulbs of 500 W and 200 W rated at 250 V will have resistance ratio as________?

A. 4 : 25
B. 25 : 4
C. 2 : 5
D. 5 : 2

A glass rod when rubbed with silk cloth is charged because__________?

A. it takes in proton
B. its atoms are removed
C. it gives away electrons
D. it gives away positive charge