(English Medium) ICSE Class 10 - CISCE Question Bank Solutions for Physics

What is the voltage of the electricity that is generally supplied to a house?

What is consumed while using different electrical appliances, for which electricity bills are paid? 

How do kilowatt and kilowatt-hour differ?

List the names of three electrical gadgets used in your house. Write their power, voltage rating and approximate time for which each one is used in a day. Hence find the electrical energy consumed by each in a month of 30 days.

Two lamps, one rated 220 V, 50 W and the other rated 220 V, 100 W, are connected in series with mains of 220 V. Explain why does the 50 W lamp consume more power.

When a current I flows through a resistance R for time t, the electrical energy spent is given by ______.

What is the resistance, under normal working conditions, of an electric lamp rated at '240 v, 60 W' ? If two such lamps are connected in series across a 240 V mains supply, explain why each one appears less bright.

Two bulbs are rated 60 W, 220 V and 60 W, 110 V respectively. Calculate the ratio of their resistances.

An electric toaster draws current 8 A in a circuit with source of voltage 220 V. It is used for 2 h. Find the cost of operating the toaster if the cost of electrical energy is ₹ 4.50 per kWh.

Sumit does 600 J of work in 10 min and Amit does 300 J of work in 20 min. Calculate the ratio of the powers delivered by them.

Name the physical quantity which is measured in kWh.

Name the physical quantity which is measured in Wh.

A bulb of power 60 W is used for 12.5 h each day for 30 days. Calculate the electrical energy consumed.

Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate:

1. the total current taken from the supply
2. the resistance of each heater and
3. the energy supplied in kWh to the three heaters in 5 hours.

Name the factors on which the heat produced in a wire depends when current is passed in it, and state how does it depend on the factors stated by you.

(a) Observe the diagram given below and state whether the bulb will glow or not when we switch on K.

(b) Is it safe to handle the bulb when the switch is OFF?

(c) Give a reason for your answer in (b).

When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.

The graph of voltage vs current for four different materials is shown below.

Which of these four materials would be used for making filament of bulb?

An electric iron is rated 220 V, 2 kW. If the iron is used for 3h daily find the cost of running it for one week if it costs ₹ 4.25 per kWh.

State the energy changes in the following case while in use:

An electric iron