The two principal thrusts in physics are

If $e$ is the charge,$V$ is the potential difference,and $T$ is the temperature,then the units of $\frac{eV}{T}$ are the same as that of:

Give an example of:
$(a)$ a physical quantity which has a unit but no dimensions
$(b)$ a physical quantity which has neither unit nor dimensions
$(c)$ a constant which has a unit
$(d)$ a constant which has no unit

Choose the correct match:

List-$I$	List-$II$
$(i)$ Curie	$(A)$ $MLT^{-2}$
$(ii)$ Light year	$(B)$ $M$
$(iii)$ Dielectric strength	$(C)$ Dimensionless
$(iv)$ Atomic weight	$(D)$ $T$
$(v)$ Decibel	$(E)$ $ML^2T^{-2}$
	$(F)$ $MT^{-3}$
	$(G)$ $T^{-1}$
	$(H)$ $L$
	$(I)$ $MLT^{-3}I^{-1}$
	$(J)$ $LT^{-1}$

Just as precise measurements are necessary in science,it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain,try to get an upper bound on the quantity):
$(a)$ The total mass of rain-bearing clouds over India during the Monsoon.
$(b)$ The mass of an elephant.
$(c)$ The wind speed during a storm.
$(d)$ The number of strands of hair on your head.
$(e)$ The number of air molecules in your classroom.

Match List $I$ with List $II$:

List $I$	List $II$
$A$. Torque	$I$. $[M^1 L^1 T^{-2} A^{-2}]$
$B$. Magnetic field	$II$. $[L^2 A^1]$
$C$. Magnetic moment	$III$. $[M^1 T^{-2} A^{-1}]$
$D$. Permeability of free space	$IV$. $[M^1 L^2 T^{-2}]$

Choose the correct answer from the options given below: