What is zeolite among the following?

$A$ horizontal straight wire $20\, m$ long extending from east to west is falling with a speed of $5.0\, m/s$,at right angles to the horizontal component of the earth's magnetic field $0.30 \times 10^{-4}\, Wb/m^2$. The instantaneous value of the $e.m.f.$ induced in the wire will be.....$mV$.

The number of ways of choosing $10$ objects out of $31$ objects,of which $10$ are identical and the remaining $21$ are distinct,is

The length of the perpendicular from the point $(2,-1,4)$ to the straight line $\frac{x+3}{10}=\frac{y-2}{-7}=\frac{z}{1}$ is:

When radiation of wavelength $\lambda$ is incident on a metallic surface,the stopping potential is $4.8 \ V$. If the surface is illuminated with radiation of double the wavelength,then the stopping potential becomes $1.6 \ V$. The threshold wavelength for the surface is: