ICSE ICSE Class 8 - CISCE Question Bank Solutions

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.

Water in a dish evaporates faster than in a bottle. Give reason. 

Why are volatile liquids such as alcohol and spirit stored in tightly closed bottles?

Why is cooling produced on evaporation of a liquid?

Explain with an example to demonstrates that when a liquid evaporates, it takes heat from its surroundings.

Give two applications of evaporation.

Explain why in hot summer days water remains cool in earthen pots.

A patient suffering from high fever is advised to put wet clot strips on his forehead. Why?

Power P= ............ /time taken.

The S.I. unit of power is ..........

1 H.P. = .........

Match the following

Two coolies A and B do some work in time 1 minute and 2 minute respectively. The power spent is