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

Calculate the work done when:
A 5 kg weight is lifted 10 m vertically. (g = 9.8 m/s²)

A force is applied on a body of mass 20 kg moving with a velocity of 40 ms⁻¹. The body attains a velocity of 50 ms⁻¹ in 2 seconds. Calculate the work done by the body.

The work done by the heart is 1 Joule per beat. Calculate the power of the heart if it beats 72 times in one.

How long should an electric motor, of power 2 H.P. operate, so as to pump 5 m³ of water from a depth of 15m. [Take g = 10 N kg⁻¹]

How do you define force? What are the forces acting on a man standing in a lift? If the lift moves down with an acceleration of 2 ms⁻², what is the net force on the man if his mass is 50 kg?

A coolie is pushing a box weighing 1500 N up an inclined plane 7.5 m long on to a platform, 2.5 m above the ground.
(i) Calculate the mechanical advantage of the inclined plane. (ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort.

An electric motor of power 100 W is used to drive the stirrer in a water bath. If 50% of the energy supplied to the motor is spent in stirring the water. Calculate the work done on the water in one minute.

The weights of two bodies are 2.0 N and 2.0 kgf respectively what is the mass of each body?

A girl of mass 40 kg runs a height of 80 stairs, each 25 cm high with a load of 20 kg on her head in 25 sec. If g is 10 m/s², find:
(i) Gravitational force acting on the girl.
(ii) Work done by her.
(iii) Useful work done by her.
(iv) Her power in watt.

A water pump raises 50 kg of water through a height of 25 m in 5s. Calculate the power supplied by the pump (Take: g = 10 N kg⁻¹).

An electric motor pump is 60% efficient and is rated 2.5 H.P. Calculate the maximum load it can lift through a height of 10m in 8 sec. (1 H.P. = 750 W).

What is a machine?

Name a machine which can be used to multiply force and change the direction of force applied.

Light of different colours is deviated through different angles by a prism. Explain the reason.

Give a reason, why the violet colour of white light deviated most and red colour of white light deviated least.

What is understood by the term dispersion of light? What is its cause?

Name the radiation of a wavelength longer than 8 × 10⁻⁷ m.

Explain, why quartz prism is required for obtaining the spectrum of ultra-violet light?

A prism causes dispersion of white light while a rectangular glass block does not. Explain.

Draw a neat diagram to show the arrangement you would use to project a pure spectrum of white light on a screen.