Assertion (A): The deflecting torque acting on a current carrying loop is zero when its plane is perpendicular to the direction of magnetic field.

Reason (R): The deflecting torque acting on a loop of magnetic moment $$\vec{m}$$ in a magnetic field $$\vec{B}$$ is given by the dot product of $$\vec{m}$$ and $$\vec{B}$$.

Draw a graph showing the variation of potential energy of a pair of nucleons as a function of their separation. Indicate the region in which the nuclear force is (a) attractive and (b) repulsive.

(a) How will the De Broglie wavelength associated with an electron be affected when the (i) velocity of the electron decreases ? and (ii) accelerating potential is increased? Justify your answer.

OR

(b) How would the stopping potential for a given photosensitive surface change if (i) the frequency of the incident radiation were increased? and (ii) the intensity of incident radiation were decreased? Justify your answer.

Identify the electromagnetic wave whose wavelengths range is from about

(a) $$10^{-12} \mathrm{~m}$$ to about $$10^{-8} \mathrm{~m}$$.

(b) $$10^{-3} \mathrm{~m}$$ to about $$10^{-1} \mathrm{~m}$$.

Write one use of each.