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

The speed of sound in air at 0°C is nearly :

The speed of light in air is :

The heart of a man beats 75 times a minute. What is its (a) frequency and (b) time period? 

The separation between two consecutive crests in a transverse wave is 100 m. If wave velocity is 20 m s^-1, find the frequency of wave. 

An observer A fires a gun and another observer B at a distance 1650 m away from A hears its sound. If the speed of sound is 330 m s^-1, find the time when B will hear the sound after firing by A. 

An observer sitting in line of two tanks watches the flashes of two tanks firing at each other at the same time, but he hears the sounds of two shots 2s and 3.5s after seeing the flashes. If distance between the two tanks is 510m, find the speed of sound. 

What do you mean by the audible range of frequency? 

Select the correct option.

Unit of thrust in the SI system is

Select the correct option.

The unit Nm² is the unit of

Select the correct option.

Thrust acting perpendicularly on the unit surface area is called

What do you understand by the Light?

What do you understand by the Diffused Light?

Define Regular reflection.

Why are infinite images not seen when two plane mirrors are facing each other?

State three ways in which the image formed in a plane mirror differs from the image formed in a pin hole camera.

State four uses of a plane mirror.

Draw a neat diagram of reflecting periscope.