English Medium इयत्ता ९ - CBSE Question Bank Solutions

Name the tissue present in the brain.

A submarine emits a sonar pulse, which returns from an underwater cliff in 1.02 s. If the speed of sound in salt water is 1531 m/s, how far away is the cliff?

Give two practical applications of reflection of sound waves.

Explain how bats use ultrasound to catch a prey.

How is ultrasound used for cleaning?

Explain the working and application of a sonar.

A sonar device on a submarine sends out a signal and receives an echo 5 s later. Calculate the speed of sound in water if the distance of the object from the submarine is 3625 m.

Explain how defects in a metal block can be detected using ultrasound.

How are fish obtained?

What are the advantages of composite fish culture?

How do you differentiate between capture fishing, mariculture and aquaculture?

Earth moves around the sun with uniform velocity.

Mention four advantages of fishery.

What are the advantages of composite fish culture?

How do you differentiate between capture fisheries, inland fisheries and aquaculture?

Define the following term: 

Cytosol

List one function of the following : 4.neuron

State two characteristics of nerve cells.

Draw and label a neuron.