ICSE ICSE Class 8 - CISCE Question Bank Solutions for Physics

What is an electric meter? Where is it fixed in our house?

State the purpose of kWh meter.

For which unit do we pay our electricity bill?

The diagram below in figure shows the reading on the dials of a meter. State what is its reading.

One day the meter reading is found to be 7643 units while the next day, it was 7657 units. What is the consumption of electricity in a day?

Name the unit in which you pay the cost of your electricity bill. How is it related to joule?

If an appliance of power P watt is used for time t hour. How much electrical energy is consumed in kWh?

What is an electric fuse? State its purpose in the household electrical circuit.

Figure shows two ways of connecting the three bulbs A, B and C to a battery. Name the two arrangements. Which of them do you prefer to use in a household circuit? Give a reason to support your answer.

Draw a labelled diagram with the necessary switches to connect a bulb, a fan and a plug socket in a room with the mains. In what arrangement will you connect them to the mains?

An electric iron of power 1.5 kW is used for 30 minutes to press the clothes. Calculate the electrical energy consumed in

1. kilowatt-hour
2. joule.

Assuming the electric consumption per day to be 12 kWh and the rate of electricity to be? 6.25 per unit, find how much money is to be paid in a month of 30 days?

In a premise 5 bulbs each of 100 W, 2 fans each of 60 W, 2 A.Cs each of 1.5 kW is used for 5 h per day. Find:

1. Total power consumed per day,
2. Total power consumed in 30 days,
3. Total electrical energy consumed in 30 days.
4. The cost of electricity at the rate of ₹ 6.25 per unit.

An electrical appliance is rated as 60 W – 150 V.

How much current will flow through the appliance when in use?

Our body can pass electricity through it.

Evaporation takes place from the

A liquid can change into vapour state at all temperatures.

What is evaporation?

State three factors which affect the rate of evaporation of a liquid.

Wet clothes dry more quickly on a warm dry day than on a cold humid day. Explain.