(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

Answer the following question :
How does the speed of sound differ in different media?

Complete the following sentences :

When sound travels in a medium, the particles of medium ___________ but the disturbance ___________.

Sound in air propagates in form of 

The time interval between a lightning flash and the first sound of thunder was found to be 5 s. If the speed of sound in air is 330 m s^-1, find the distance of flash from the observer. 

A boy fires a gun and another boy at a distance hears the sound of fire 2.5s after seeing the flash. If the speed of sound in air 340 m/s, find distance between the boys. 

How long will sound take to travel in (a) and iron rail and (b) air, both 3.3 km in length? Take speed of sound in air to be 330 m/s and in iron to be 5280 m/s.

Assuming the speed of sound in air equal to 340 m/s and in water equal to 1360 m/s, find the time taken to travel a distance 1700 m by sound in (i) air (ii) water.

Fill in the blank to complete the sentence :

The two ends of a magnet are called __________.

Fill in the blank to complete the sentence :

Unlike poles of a magnet ___________ each other.

Fill in the blank to complete the sentence :

Like poles of a magnet ______________ each other.

Fill in the blank to complete the sentence :

A freely suspended magnet rests in the geographic ___________ direction.

Define heat energy on a conventional basis.

Define heat energy on the basis of kinetic theory of matter.

Define temperature on a conventional basis.