If $\frac{^{n+2}C_6}{^{n-2}C_2} = 11$,then $n$ satisfies the equation

$A$ magnetic needle lying parallel to a magnetic field is turned through $60^{\circ}$. The work done on it is $W$. The torque required to maintain the magnetic needle in the position mentioned above is

$A$ thin metallic spherical shell contains a charge $Q$ on it. $A$ point charge $+q$ is placed at the centre of the shell and another charge $q'$ is placed outside it as shown in the figure. All the three charges are positive. The force on the charge at the centre is:

In an $LC$ circuit,the capacitor has a maximum charge $q_0$. The value of $\left. \frac{di}{dt} \right|_{\max }$ is:

$A$ clock which keeps correct time at $20^{\circ} C$,is subjected to $40^{\circ} C$. If the coefficient of linear expansion of the pendulum is $12 \times 10^{-6} /{ }^{\circ} C$,how much time will it gain or lose per day?

At metaphase,chromosomes are attached to the spindle fibres by their