English Medium इयत्ता ९ - CBSE Question Bank Solutions

Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is 440 m/s in a given medium.

Distinguish between loudness and intensity of sound.

What are the conditions for 'something' to be called 'matter'?

What are the conditions for 'something' to be called 'matter'?

Name two processes which provide the best evidence for the motion of particles in matter.

Name two processes which provide the best evidence for the motion of particles in matter.

What is the scientific name of particles which make up mater?

What is the scientific name of particles which make up mater?

Out of solids, liquids and gases, which one has :

1. maximum movement of particles ?
2. maximum interparticle attractions ?
3. minimum spaces between particles ?

Out of solids, liquids and gases, which one has :

1. maximum movement of particles ?
2. maximum interparticle attractions ?
3. minimum spaces between particles ?

Fill in the following blank with suitable words :

The best evidence that the particles of matter are constantly moving comes from the studies of ................. and ...................

Fill in the following blank with suitable words :

The best evidence that the particles of matter are constantly moving comes from the studies of ................. and ...................

State two characteristics of matter demonstrated by Brownian motion.

State two characteristics of matter demonstrated by Brownian motion.

Name the scientist who studied the movement of pollen grains suspended in water through a microscope. What is this phenomenon known as?

Name the scientist who studied the movement of pollen grains suspended in water through a microscope. What is this phenomenon known as?

When a crystal of potassium permanganate is placed in a beaker, its purple colour spreads throughout the water. What does this observation tell us about the nature of potassium permanganate and water?

When a crystal of potassium permanganate is placed in a beaker, its purple colour spreads throughout the water. What does this observation tell us about the nature of potassium permanganate and water?

When a gas jar containing air is inverted over a gas jar containing bromine vapour, the red-brown bromine vapour diffuse into air. Explain how bromine vapour diffuse into air.