Nuclei — Physics STD 12 Science — Question

The molecules having centres of positive charges and negative charges at same place, has the dipole moment as:

Which of the following logic gate is an universal gate

(a) OR

(b) NOT

(c) AND

(d) NOR

A bar magnet is moved along the axis of a copper ring placed far away from the magnet, Looking from the side of the magnet an anticlockwise current is found to be induced in the ring. Which of the following may be true?

1. The south pole faces the ring and the magnet moves towards it.
2. The north pole faces the ring and the magnet moves towards it.
3. The south pole faces the ring and the magnet moves away from it.
4. The north pole faces the ring and the manget moves away from it.

Carbon -14 decays with half-life of about 5,800 years. In a sample of bone, the ratio of carbon -14 to carbon -12 is found to be   of what it is in free air. This bone may belong to a period about x centuries ago, where x is nearest to

(a) 2 × 58

(b) 58

(c) 58/2

(d) 3 × 58

A plane wave front falls on a convex lens. The emergent wave front is:

According to the theory of relativity, all laws of nature are the same in reference frames that::

For the stability of radiated nucleus:

The SI unit of dipole moment is:

A star emitting light of wavelength 5896 Å is moving away from the earth with a speed of 3600 km /sec. The wavelength of light observed on earth will (c = 3  is the speed of light)

(a) Decrease by 5825.25 Å	(b) Increase by 5966.75 Å
(c) Decrease by 70.75 Å	(d) Increase by 70.75 Å

An electron makes a transition from orbit n = 4 to the orbit n = 2 of a hydrogen atom. The wave number of the emitted radiations (R = Rydberg's constant) will be

(a)

(b)

(c)

(d)