Human Eye and Colourful World — Science STD 10 — Question

A beam of parallel light rays is incident through the holes on one side of a box and emerges out through the holes on its opposite side as shown in the diagram below:

Which of the following could be inside the box?

Which of the following changes occur when you walk out of bright sunshine into a poorly lit room?

An electric generator converts:

A lens of power +2D are placed in close contact with each other. The combination will behave like:

With both eyes open, a person's field of view is about:

The red colour of the sun at the time of sunrise and sunset is because:

Linear magnification produced by a concave mirror may be:

The human eye possesses the power of accommodation. This is the power to:

1. Alter the diameter of the pupil as the intensity of light changes.
2. Distinguish between lights of different colours.
3. Focus on objects at different distances.
4. Decide which of the two objects is closer.

The constituent of biogas which makes it an excellent fuel is:

1. Butane.
2. Methane.
3. Propane.
4. Ethane.