Two spheres $S_{1}$ and $S_{2}$ have the same radii but temperatures $T_{1}$ and $T_{2}$ respectively. Their emissive power is the same and their emissivity is in the ratio $1: 4$. Then the ratio of $T_{1}$ to $T_{2}$ is:

In which of the following is the sporophyte parasitic on the gametophyte?

$X$-rays of wavelength $0.140 \ nm$ are scattered from a block of carbon. What will be the wavelength of $X$-rays scattered at $90^{\circ}$ (in $nm$)?

What is the vital capacity of our lungs?

If $(2,-1,3)$ is the foot of the perpendicular drawn from the origin to the plane, then the equation of the plane is

When a certain circuit consisting of a constant $emf$ $E$,an inductance $L$,and a resistance $R$ is closed,the current in it increases with time according to curve $1$. After one parameter ($E$,$L$,or $R$) is changed,the increase in current follows curve $2$,when the circuit is closed a second time. Which parameter was changed and in what direction?