ICSE ICSE Class 7 - CISCE Question Bank Solutions for Physics

Fill in the blank

The image formed by a plane mirror is erect and _____

State the energy changes that occur in the following :

The unwinding of a watch spring.

State the energy changes that occur in the following :

Burning coal while operating a steam engine.

State the energy changes that occur in the following :

Lighting of a torch bulb.

State the energy changes that occur in the following :

An electric generator (or dynamo).

Fill in the blank

A ________ image cannot be obtained on a screen.

 Select the correct alternative

The angle between the incident ray and the ray reflected from the plane mirror is 70°. The angle of incidence will be :

Draw a diagram to show the reflection of a light ray incident normally on a plane mirror. 

The diagram in Fig. shows an incident ray AO and the reflected ray OB from a plane mirror. The angle AOB is 30°. Draw normal on the plane mirror at the point O and find:

The diagram in fig. shows an incident ray AO and the normal ON on a plane mirror. Draw the reflected ray. State the law you use to draw the direction of the reflected ray.

Write true or false for a given statement.

Sound can travel in a vacuum.

Fill in the blank.

Sound travels faster in ________ than in liquids.

Select the correct alternative : 

The speed of sound in water is

Describe an experiment to show that sound can travel in water.

Describe an experiment to show that sound can travel in a solid.

Write the approximate speed of sound in air.

Write the approximate speed of sound in water . 

Write the approximate speed of sound in steel.

During a thunderstorm, the sound of a thunder is heard after the lightning is seen. Why?

Can sound travel through solids and liquids ? In which of these two does it travel faster ?