Human Eye and Colourful World — Science STD 10 — Question

When a 1 ohm resistor is connected across the potential difference of 20V, what will be power dissipation in it:

The colour of white light which is deviated the maximum on passing through the glass prism is:

1. Blue.
2. Indigo.
3. Red.
4. Orange.

The real image formed by a concave mirror is smaller than the object if the object is:

1. Between centre of curvature and focus.
2. At a distance greater than radius of curvature.
3. At a distance equal to radius of curvature.
4. At a distance equal to focal length.

You are given water mustard oil, glycerine and kerosene. In which of these media a ray of light incident obliquely at same angle would bend the most?

________are substances which do not allow electricity to pass through them:

The refractive indexes of four substances P, Q, R and S are 1.77, 1.50, 2.42 and 1.31 respectively. When light travelling in air is incident on these substances at equal angles, the angle of refraction will be the maximum in:

1. Substance P.
2. Substance Q.
3. Substance R.
4. Substance S.

A boy records that 4000 joule of work is required to transfer 10 coulomb of charge between two points of a resistor of 50 Ω. The current passing through it is:

The back face of a circular loop of wire is found to be south magnetic pole. The direction of current in this face of the circular loop of wire will be:

1. Towards south.
2. Clockwise.
3. Anticlockwise.
4. Towards north.

One of the following is not a characteristic of a good fuel. This is:

1. High calorific value.
2. No emission of smoke.
3. Smooth burning.
4. High ignition temperature.

Name the material used for making the connection wires: