On heating a liquid of coefficient of cubical expansion $\gamma$ in a container having coefficient of linear expansion $\gamma / 3$,the level of liquid in the container will

To increase milk yield,a cow is given:

The distance between the foci of the hyperbola $x^2 - 3y^2 - 4x - 6y - 11 = 0$ is

Which of the following pairs of orbitals possess two nodal planes?

$A$ black body of mass $34.38 \ g$ and surface area $19.2 \ cm^2$ is at an initial temperature of $400 \ K$. It is allowed to cool inside an evacuated enclosure kept at a constant temperature of $300 \ K$. The rate of cooling is $0.04 \ ^{\circ}C/s$. The specific heat of the body in $J \ kg^{-1} \ K^{-1}$ is (Stefan's constant $\sigma = 5.73 \times 10^{-8} \ W \ m^{-2} \ K^{-4}$)

An assembly of identical spring-mass systems is placed on a smooth horizontal surface as shown. At this instant,the springs are relaxed. The left mass is displaced to the left and the right mass is displaced to the right by the same distance and released. The resulting collision is elastic. The time period of the oscillations of the system is