Physics

In a cyclic process,   $\Delta U=0.$

In a cyclic process work done is equal to the area under the cycle and is positive if the cycle is clockwise and negative if anticlockwise 

$\Delta W=$ Area of rectangle $ABCD=-P\left(2V\right)$

$=-2PV$

According to first law of thermodynamics

$\Delta Q=\Delta U+\Delta W$ or $\Delta Q=\Delta W$ $\left(As\Delta U=0\right)$

i.e., heat supplied to the system is equal to the work done

So heat absorbed, $\Delta Q=\Delta W=-2PV$

Heat rejected by the gas $=2PV$

The primary reason for this is that silver is a quite expensive material to be used on such a large scale. Also, it doesn't have a much longer lifespan and tarnishes easily. So copper is used for electrical wiring because it offers low resistance to electric current is comparatively much more safer option to be commercially used.

Rate of heat radiated at (227 + 273) K

$=7cals/\left(c{m}^{2}s\right)$

Let rate of heat radiated at (727+ 273)  K = xcals/ (cm²s)

By Stefan's law 

$R=n^{1/3}r$

$E=T.\Delta A=ms\Delta TJ$

Energy stored in unit volume of wire

Water level in both section A and B will be goes up due being of centrifugal force water will goes away and it acquire the force from upside so the water will does up so water level in both the section A and B goes up.

By given $U=54joulem=3kg$

By conservation of mechanical energy law

$\left(K+U\right)$ Earth surface $=\left(K+U\right)\infty$

$\frac{1}{2}m{v}^2+\left(-54J\right)=0+0$

$\frac{1}{2}m{v}^2=54$

$3v^2=108$

$v^2=\frac{108}{3}=36$

v= 6m/s

$As{V}^2=V_R^2+C_C^2$

$?V_R=\sqrt[]{V^2-V_C^2}=\sqrt[]{{10}^2-8^2}=6V$

$\tan ?\theta =\frac{X_C}{X_R}=\frac{V_C}{V_R}=\frac{8}{6}=\frac{4}{3}$

R =? *L/A

This is the formula of calculating a wire's resistance. If you look closely at the formula,

A= cross sectional area

More the surface area, more will be the area for passage of free electrons.

Hence, we can easily conclude that thickness of a wire plays an jmportant role in determining it's conductivity.