Human Eye and Colourful World — Science STD 10 — Question

Which of the following characteristic is not suitable for a fuse wire?

1. Thin and short.
2. Thick and short.
3. Low melting point.
4. Higher resistance than rest of wiring.

A prism ABC (with BC as base) is placed in different orientations. A narrow beam of white light is incident on the prism as shown in figure. In which of the following cases, after dispersion, the third colour from the top corresponds to the colour of the sky?

The north-south polarities of an electromagnet can be found easily by using:

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.

Motion of charges is nothing but:

Two resistors are connected in series gives an equivalent resistance of 10Ω. When connected in parallel, gives 2.4Ω. Then the individual resistance are:

The resistivity of copper metal depends on only one of the following factors. This factor is:

The part of box-type solar cooker which is responsible for producing greenhouse effect is:

1. Plane mirror reflector.
2. Black coating inside the box.
3. Glass sheet cover.
4. Utensils placed in the cooker box.

The image of an object formed by a plane mirror is:

1. Virtual.
2. Real.
3. Diminished.
4. Upside-down.

The fuel having the lowest calorific value is:

1. Coal.
2. Wood.
3. Charcoal.
4. Kerosene.