Electricity and Magnetism — PHYSICS STD 7 — Question

An observer puts ear on a railway line 500 m from a friend with a hammer. When his friend hits the railway line with the hammer, the observer hears two sounds. The sound is first heard through :

The formula for calculating the volume of a cube is :

A spinning wheel describes a :

A book lying on a table is an example of

The SI unit of speed or velocity is :

Which is not a translucent medium?

Electrical devices installed in houses, factories and offices are connected in

A dry cell converts chemical energy into

Select the correct alternative
A boy travels a distance 150 m in 1 minute. His speed is

Which of the following is not true for a magnet?