English Medium Class 9 - CBSE Question Bank Solutions for Science

In the sound wave produced by a vibrating turning fork shown in the diagram, half the wavelength is represented by :

When the pitch of note produced by a harmonium is lowered, then the wavelength of the note : 

Figure X shows a trace of a sound wave produced by a particular tuning fork :

(a) On the graph paper given in Figure Y, draw a trace of the sound wave which has a higher frequency than that shown in figure X.
(b) On the graph paper show in Figure Z, draw a trace of the sound wave which has a larger amplitude than that shown in Figure X.

Which kind of sound is produced in an earthquake before the main shock wave begins ?

A key of mechanical piano is first struck gently and then struck again but much harder this time. In the second case :

Answer the following question.

Who discovered cells, and how?

Answer the following question.

Why is the cell called the structural and functional unit of life?

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

Suma is swimming in a pond.

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

A donkey is carrying a load on its back.

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

A wind-mill is lifting water from a well.

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

A green plant is carrying out photosynthesis.

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

An engine is pulling a train.

Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

Food grains are getting dried in the sun.

The property to flow is unique to fluids. Which one of the following statements is correct?

You are provided with a mixture of naphthalene and ammonium chloride by your teacher. Suggest an activity to separate them with well labelled diagram.

In desert plants, rate of water loss gets reduced due to the presence of

Flexibility in plants is due to

Differentiate the following activities on the basis of voluntary (V) or involuntary (IV) muscles.

Jumping of frog

Differentiate the following activities on the basis of voluntary (V) or involuntary (IV) muscles.

Pumping of the heart

______ have tubular cells with perforated walls and are living in nature.