revision physics

what is the use of watt hour meter in the household circuit?

• to measure electrical energy consumed in kilowatt hour

• to measure voltage

• to reduce the current

• to increase the current

which part of the equipments are connected to earth line?

• metallic part

• wires

• plastic part

• transformer

how is earth pin different from other pins?

• the length of the earth pin is more than that of other pins.

• the thickness of the earth pin is more than that of other pins

• both a and b

• none of these

identify the graphs which represent direct current,

• fig 1 only

• fig 2 only

• both fig 2 and 3

• both fig 1 and 3

transformer- mutual induction

inductor - ------------------------

• mutual induction

• self induction

• electromagnetic induction

• motor principle