An unpolarised beam of intensity $$2 a^2$$ passes through a thin polaroid. Assuming zero absorption in the polaroid, the intensity of emergent plane polarised light is
A gas consisting of a rigid diatomic molecules was initially under standard condition. Then, gas was compressed adiabatically to one-fifth of its initial volume. What will be the mean kinetic energy of a rotating molecule in the final state?
A diode detector is used to detect and amplitude modulated wave of 60% modulation by using a condenser of capacity 250 pF in parallel with a load resistance 100 k$$\Omega$$. Find the maximum modulated frequency which could be detected by it.
Red light of wavelength 5400 $$\mathop A\limits^o $$ from a distant source falls on a slit 0.80 mm wide. Calculate the distance between first two dark bands on each side of central bright band in the diffraction pattern observed on a screen place 1.4 m from the slit.