AIPMT 2011 Mains Mock Test

Which is not a possible energy for a photon emitted by $\text{H}$ -atom?

In which of the following figures are the diodes forward biased?

Two nuclei $P$ ($4N_0,T_{1/2}=1\text{m}$) and $Q$ ($N_0,T_{1/2}=2\text{m}$) decay to $R$. When $P=Q$, the number of $R$ nuclei present is:

Pure $\text{Si}$ at $500\text{K}$ has $n_i=1.5\times 10^{16}{\text{m}}^{-3}$. Doping by Indium increases $n_h$ to $4.5\times 10^{22}{\text{m}}^{-3}$. The doped semiconductor is:

A $15^{\circ }$ prism (${\mu }_1=1.5$) is combined with another (${\mu }_2=1.75$) to produce dispersion without deviation. The angle of the second prism is: