Column - I gives certain physical terms associated with flow of current through a metallic conductor. Column-II gives some mathematical relations involving electrical quantities. Match column-I and column-II with appropriate relations.

	Column - I		Column - II
(A)	Drift Velocity	(P)	$${m \over {n{e^2}p}}$$
(B)	Electrical Resistivity	(Q)	$$ne{\upsilon _d}$$
(C)	Relaxation Period	(R)	$${{eE} \over m}\tau $$
(D)	Current Density	(S)	$${E \over J}$$

Match Column - I and Column - II and choose the correct match from the given choices.

	Column - I		Column - II
(A)	Root mean square speed of gas molecules	(P)	$${1 \over 3}nm{\overline v ^2}$$
(B)	Pressure exerted by ideal gas	(Q)	$$\sqrt {{{3RT} \over M}} $$
(C)	Average kinetic energy of a molecule	(R)	$${5 \over 2}RT$$
(D)	Total internal energy of 1 mole of a diatomic gas	(S)	$${3 \over 2}{k_B}T$$

In the product

$$\overrightarrow F = q\left( {\overrightarrow v \times \overrightarrow B } \right)$$

$$ = q\overrightarrow v \times \left( {B\widehat i + B\widehat j + {B_0}\widehat k} \right)$$

For q = 1 and $$\overrightarrow v = 2\widehat i + 4\widehat j + 6\widehat k$$ and $$\overrightarrow F = 4\widehat i - 20\widehat j + 12\widehat k$$

What will be the complete expression for $$\overrightarrow B $$ ?

From a circular ring of mass 'M' and radius 'R' an arc corresponding to a 90$$^\circ$$ sector is removed. The moment of inertia of the remaining part of the ring about an axis passing through the center of the ring and perpendicular to the plane of the ring is 'K' times 'MR²'. Then the value of 'K' is :