Atoms — Physics STD 12 Science — Question

Statement-1: NOT gate is also called invertor circuit.

Statement-2: NOT gate inverts the input order.

The magnifying power of a microscope with an objective of 5 mm focal length is 400. The length of its tube is 20 cm. Then the focal length of the eye-piece is

(a) 200 cm

(b) 160 cm

(c) 2.5 cm

(d)  0.1 cm

Microwaves are electromagnetic waves with frequency in the range of:

The equivalent resistance between points A and B of an infinite network of resistances each of 1Ω connected as shown, is

(a) Infinite

(b) 2 Ω

(c)

(d) Zero

Work done in moving an object through an equipotential surface is:

A concave and convex lens have the same focal length of 20 cm and are put into contact to form a lens combination. The combination is used to view an object of 5 cm length kept at 20 cm from the lens combination. As compared to the object, the image will be

(a) Magnified and inverted

(b) Reduced and erect

(c) Of the same size as the object and erect

(d) Of the same size as the object but inverted

When stopping potential is applied in an experiment on photoelectric effect, no photocurrent is observed. This means that:

1. The emission of photoelectrons is stopped.
2. The photoelectrons are emitted but are reabsorbed by the emitter metal.
3. The photoelectrons are accumulated near the collector plate.
4. The photoelectrons are dispersed from the sides of the apparatus.

Venus appears brighter than other stars because

(a) It is heavier than other planets

(b) Its density is more than other planets

(c) It is nearer to earth in comparison to other planets

(d) Nuclear fusion takes place at its surface

The equivalent quantity of mass in electricity is

(a)  Charge

(b) Potential

(c)  Inductance

(d) Current