Solution

Unpolarized light : The light having vibration of electric field vector in all possible directions perpendicular to the direction of wave propagation the light is known as unpolarized light.
Linearly polarized light : The light having vibrations of electric field vector in only one direction perpendicular to the direction of propagation of light is as plane or linearly polarized light

Solution

With the rise in temperature, the electrons collide more frequently, so relaxation time decreases, and hence drift velocity increases.

Solution

Solution

(i) Threshold frequency: The minimum frequency of incident light that is just capable of ejecting electrons from a metal is called the threshold frequency. It is denoted by V₀.
(ii) Stopping potential : The minimum retarding potential applied to the anode of a photoelectric tube that is just capable of stopping photoelectric current is called the stopping potential. It is denoted by V₀ (or Vs).

Solution

Solution

When a charged particle enters a magnetic field making angle at 30°. Then velocity component is resolved into 2 components, vcos θ (along the magnetic field) and v sin θ (normal to the magnetic field). As the charged particle moves along XY- plane due to velocity component v sin θ, it also advances linearly due to the velocity component v cos θ. As a result, the charged particle will move in a helical path as shown in the figure.

Solution

(a) In Rutherford’s scattering experiment of a-particle, it was observed that the fast and heavy a-particles could be deflected through 180°. But only very small number of particles i.e., 1 in about 8,000 a-particles are deflected through 180° that too from centre only. So by this, it was assumed that the size of central part i.e., the nucleus is about 1/10,000th of the size of the atom and whole positive charge is concentrated in it.
(b)Consider an atom whose mass number is A and R be the radius of the nucleus. If we neglect the mass of orbital electrons, then mass of the nucleus of the atom of mass number A = A a.m.u.

Solution

(a) Principle : It is based on a principle that a positive ion can acquire sufficiently large energy with a comparatively smaller alternating potential difference by making it to cross the same electric field again and again by making use of a strong magnetic field.

Working: The positive ions are produced from the source at the centre are accelerated by a dee which is at negative potential at that moment. Due to the presence of perpendicular magnetic field the ion will move in a circular path inside the dees. The magnetic field and the frequency of a.c source are so chosen that as the ions comes out of a dee, it changes its polarity and the ion is further accelerated and moves with higher velocity along a circular path of greater radius. This phenomenon is continued till the ion reaches at the periphery of the dees where an deflecting plate deflects the accelerated ion on the target to be bombarded. Expression for cyclotron frequency Suppose a position ion with charge q moving with a velocity v, then

Solution

At the same distance the force on the wire A3 is independent of the direction of the current. As if the current is in opposite direction then F1 and F2 will be in opposite direction but will be in equilibrium.

Solution

(a)
(b)
The Magnitudes of the electric field due to the two charges +q and -q is given by

The directions of E+q and E-q are as shown in the figure. The components normal to the dipole axis cancel away. The components along the dipole axis add up.