Measurements and Experimentation — PHYSICS STD 9 — Question

Describe an experiment to show that a blackened surface is a better emitter of heat than a polished surface.

Draw a diagram to show the reflection of a ray of light using a plane mirror. In the diagram, label the incident ray, the reflected ray, the normal, the angle of incidence and the angle of reflection.

For what position of an object, a concave mirror forms an enlarged virtual image?

How will the following factors affect the speed of sound in air:
Temperature of air.

Give scientific reason:
Soft iron is used to make electromagnets.

A boy uses a vernier callipers to measure the thickness of his pencil. He measures it to be 1.4 mm. If the zero error of vernier callipers is +0.02 cm, what is the correct thickness of the pencil?

Write symbol and state function of following component in an electric circuit :
cell

A person hearing at one end of a long metal bar hears two distinct sounds when the other end is struck with a stone. Explain, giving scientific reasons

A solid weighs 105 kgf in air. When completely immersed in water, it displaces 30,000 cm of water, calculate relative density of solid.

Name the two kinds of spherical mirrors and distinguish between them.