In a transistor,if $\frac{I_C}{I_E} = \alpha$ and $\frac{I_C}{I_B} = \beta$. If $\alpha$ varies between $\frac{20}{21}$ and $\frac{100}{101}$,then the value of $\beta$ lies between:

The geometry possessed by $[Ni(CO)_4]$ is

Two particles $A$ and $B$ of equal masses are suspended from two massless springs of spring constants $k_1$ and $k_2,$ respectively. If the maximum velocities during oscillations are equal,the ratio of amplitudes of $A$ and $B$ is

$A$ telescope has an objective lens of focal length $144\, cm$ and an eyepiece of focal length $6\, cm$. Find the magnifying power of the telescope for normal adjustment.

The locus of the point $z = x + iy$ satisfying the equation $\left|\frac{z-1}{z+1}\right| = 1$ is given by:

Three unequal resistors in parallel are equivalent to a resistance $1 \, \Omega$. If two of them are in the ratio $1 : 2$ and if no resistance value is fractional,the largest of the three resistances in $ohms$ is