Human Eye and Colourful World — Science STD 10 — Question

While performing the experiment to trace the path of a ray of light passing through a glass prism, four students marked the incident ray and the emergent ray in their diagrams in the manner shown below:

The unit for expressing electric power is:

1. Volt.
2. Joule.
3. Coulomb.
4. Watt.

The shape of the earth's magnetic field resembles that of an imaginary:

1. U-shaped magnet.
2. Straight conductor carrying current.
3. Current-carrying circular coil.
4. Bar magnet.

Linear magnification produced by a concave mirror may be:

1. Less than 1 or equal to 1.
2. More than 1 or equal than 1.
3. Less than 1, more than 1 or equal to 1.
4. Less than 1 or more than 1.

Refractive index of diamond with respect to glass is 1.6. If the absolute refractive index of glass is 1.5, then the absolute refractive index of diamond is:

When three identical bulb of 60 W- 220V rating are connected in series to a 220V supply, the power drawn by them will be.

What is the commercial unit of electrical energy?

A rectangular coil of copper wire is rotated in a magnetic field. The direction of induced current changes once in each:

If the diameter of a resistance wire is halved, then its resistance becomes:

When the switch S is closed in the figure given below, the pointer of the galvanometer moves to the right.

If S is kept closed, will the pointer:

1. Return to zero?
2. Stay over on the right?
3. Move to the left and stay there.
4. Move to and fro until S is opened.