Refractive index of the medium is $$\mu$$ and wavelength is $$\lambda$$, then which of the following proportionality relation is correct?

$$A$$ transistor has a voltage gain $$A$$. If the amount $$\beta A$$ of its output is applied to the input of the transistor, then the transistor becomes oscillator, when

A spherical rubber balloon carries a charge, uniformly distributed over the surface. As the balloon is blown up and increases in size, the total electric flux coming out of the surface

A diatomic gas undergoes adiabatic change. Its pressure $$p$$ and temperature $$T$$ are related as $$p \propto T^x$$, where $$x$$ is