Human Eye and Colourful World — Science STD 10 — Question

The magnetic field lines produced by a bar magnet:

1. Originate from the south pole and end at its north pole.
2. Originate from the north pole and end at its east pole.
3. Originate from the north pole and end at its south pole.
4. Originate from the south pole and end at its west pole.

A dynamo develops 0.5A at 6V.The energy which is generated in one second is:

A student has obtained the image of a distant object with a concave mirror to determine its focal length. If he has selected a well illuminated red building as object, which of the following correctly describes the features of the image formed?

The part of human eye which is sensitive to red, blue and green light is:

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 near sighted person wears eye glass of power 5.5D for distant vision. His doctor prescribes a correction of +ID in near vision part of his bifocals, which is measured relative to the main part of the lens. Then, the focal length of his near vision part of the lens is.

The magnetic field near a long straight wire is described by:

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be–

How does the eye change in order to focus on near or distant objects?

1. The lens moves in or out.
2. The retina moves in or out.
3. The lens becomes thicker or thinner.
4. The pupil gets larger or smaller.