A beam of unpolarised light of intensity $$I_0$$ is passed through a polaroid $$A$$ and then through another polaroid $$B$$ which is oriented so that its principal plane makes an angle of $$45^{\circ}$$ relative to that of $$A$$. The intensity of emergent light is:

If three moles of monoatomic gas $$\left(\gamma=\frac{5}{3}\right)$$ is mixed with two moles of a diatomic gas $$\left(\gamma=\frac{7}{5}\right)$$, the value of adiabatic exponent $$\gamma$$ for the mixture is

Three blocks $$A, B$$ and $$C$$ are pulled on a horizontal smooth surface by a force of $$80 \mathrm{~N}$$ as shown in figure

The tensions T$$_1$$ and T$$_2$$ in the string are respectively :

A particle of charge '$$-q$$' and mass '$$m$$' moves in a circle of radius '$$r$$' around an infinitely long line charge of linear charge density '$$+\lambda$$'. Then time period will be given as :

(Consider $$k$$ as Coulomb's constant)