The mechanical equivalent of heat $J$ is

It is estimated that each $cm^2$ of Earth receives about $2 \text{ calorie}$ of heat energy per minute from the Sun. This is called the solar constant. The value of the solar constant in $S.I.$ units is:

Match the following. (Take the relative strength of the strongest fundamental forces in nature as $1$)

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$(A)$ Coefficient of viscosity	$(I)$ $[ML^0T^{-3}]$
$(B)$ Intensity of wave	$(II)$ $[ML^{-2}T^{-2}]$
$(C)$ Pressure gradient	$(III)$ $[M^{-1}LT^2]$
$(D)$ Compressibility	$(IV)$ $[ML^{-1}T^{-1}]$

Choose the correct answer from the options given below:

Fill in the blanks:
$(a)$ $\frac{1\,\mu m}{1\,fm} = \,....$
$(b)$ The number of significant figures in $0.0060$ is $....$
$(c)$ To study nanotechnology,the $....$ microscope has been developed.

If we use permittivity $\varepsilon$,resistance $R$,gravitational constant $G$,and voltage $V$ as fundamental physical quantities,then: