AIPMT 2011 Mains Mock Test

In the circuit shown, if $V_A=0$, what is the potential at point $B$?

A belt moves at $2\text{m/s}$. A box is dropped on it ($\mu =0.5$). Distance the box moves relative to belt before coming to rest on it is:

A diatomic gas ($\gamma =1.4$) at $2\text{atm}$ is compressed adiabatically so temp rises from $27^{\circ }\text{C}$ to $927^{\circ }\text{C}$. Final pressure is:

Charge $q$ is spread on a ring of radius $R$ rotating at frequency $f$. Magnetic induction at center is:

A Zener diode with $V_Z=15\text{V}$ is used in a regulator with $V_{in}=20\text{V}$ and $R_s=250\Omega ,R_L=1\text{k}\Omega$. Current through diode is: