Sources of Energy — Science STD 10 — Question

In order to obtain a magnification of, -0.75 with a convex lens of focal length 8cm, the object should be placed:

1. At less than 8cm.
2. Between 8cm and 16cm.
3. Beyond 16cm.
4. At 16cm.

The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was:

1. Moving towards the solenoid.
2. Moving into solenoid.
3. At rest inside the solenoid.
4. Moving out of the solenoid.

A parallel beam of light falling on the eye gets focused on the retina because of refraction at:

An electric motor is a device which transforms:

1. Mechanical energy to electrical.
2. Heat energy to electrical energy.
3. Electrical energy to heat energy only.
4. Electrical energy to mechanical energy.

Though a woman can see the distant object clearly, she cannot see the nearby objects clearly. She is suffering from the defect of vision called:

A person cannot see distant objects clearly. His vision can be corrected by using the spectacles containing:

Two bulbs of 100W and 40W are connected in series. The current through the 100W bulb is 1A. The current through the 40W bulb will be:

Which of the following statement(s) is/are correct regarding scattering of light?
i. Scattering is responsible for the bluish appearance of the sky.
ii. Clouds having droplets of water scatter all wavelengths almost equal and so are generally white.
iii. Advanced sunrise and delayed sunset are due to atmospheric reflection.

Which unit could be used to measure current?

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