Electricity — Science STD 10 — Question

Magnitude of the magnetic force experienced by a current carrying conductor in a uniform magnetic field is maximum when the magnetic field and current direction are:

Presence of charge can be correctly identified by.

One of the following does not apply to a concave mirror. This is:

1. Focal length is negative.
2. Image distance can be positive or negative.
3. Image distance is always positive.
4. Height of image can be positive or negative.

The twinkling of stars is due to atmospheric:

1. Reflection of light.
2. Dispersion of light.
3. Interference of light.
4. Refraction of light.

In order to obtain a real image twice the size of the object with a convex lens of focal length 15 cm, the object distance should be:

How many joules of electrical energy are transferred per second by a 6V; 0.5A lamp?

1. 30J/ s
2. 12J/ s
3. 0.83J/ s
4. 3J/ s

Which of the following can form a virtual image which is always smaller than the object?

1. A plane mirror.
2. A convex lens.
3. A concave lens.
4. A concave mirror.

What is the type of field line of a magnetic field passing through the centre of current carrying circular ring?

After testing the eyes of a child, the optician has prescribed the following lenses for his spectacles:
Left eye: +2.00D
Right eye: +2.25D
The child is suffering from the defect of vision called:

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