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

Explain the meaning of the statement ‘the power of an appliance is 100 W’.

An electrical appliance having a resistance of 200 Ω  is operated at 200 V. Calculate the energy consumed by the appliance in 5 minutes in joules.

'A geyser is rated 240 W-220 V'. Explain the meaning of this statement.

Draw a diagram of a right angled isosceles prism which is used to make an inverted image erect.

State and define the household unit of electricity.

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

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.

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.

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.

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.

A ball is placed on a compressed spring. What form of energy does the spring possess? On releasing the spring, the ball flies away. Give a reason.

In what way does the temperature of water at the bottom of a waterfall differ from the temperature at the top? Explain the reason.

State the condition under which the mechanical energy is conserved.

A body falls freely under gravity from rest. Name the kind of energy it will possess while falling.

Show that the sum of kinetic energy and potential energy (i.e., total mechanical energy) is always conserved in the case of a freely falling body under gravity (with air resistance neglected) from a height h by finding it when

1. The body is at the top.
2. the body has fallen a distance x.
3. the body has reached the ground.

A ball of mass 0.20 kg is thrown vertically upwards with an initial velocity of 20 m s^-1. Calculate the maximum potential energy it gains as it goes up.

A pendulum is oscillating on either side of its rest position. The correct statement is: 

A stone of mass 500 g is thrown vertically upwards with a velocity of 15 m/s. Calculate:

1. the potential energy at the greatest height,
2. the kinetic energy on reaching the ground, and
3. the total energy at its half-way point.

A metal ball of mass 2 kg is allowed to fall freely from rest from a height of 5 m above the ground. Taking g = 10 m s⁻², calculate:

1. the potential energy possessed by the ball when it is initially at rest.
2. the kinetic energy of the ball just before it hits the ground?