In a reaction,$A + B \rightleftharpoons C + D$,$40 \%$ of $B$ has reacted at equilibrium,when $1 \ mole$ of $A$ was heated with $1 \ mole$ of $B$ in a $10 \ L$ closed vessel. The value of $K_C$ is

$A$ thin flexible wire of length $L$ is connected to two adjacent fixed points and carries a current $I$ in the clockwise direction as shown. When the system is placed in a uniform magnetic field of strength $B$ directed into the plane of the paper,the wire takes the shape of a circle. The tension in the wire after acquiring the circular shape is

The potential difference between $A$ and $B$ in the figure is .............. $V$.

The sum of the distinct real values of $\mu$,for which the vectors $\mu \hat{i}+\hat{j}+\hat{k}$,$\hat{i}+\mu \hat{j}+\hat{k}$,and $\hat{i}+\hat{j}+\mu \hat{k}$ are coplanar is

$A$ coil is suspended in a uniform magnetic field with the plane of the coil parallel to the magnetic lines of force. When a current is passed through the coil,it starts oscillating and is very difficult to stop. However,if an aluminium plate is placed near the coil,it stops. This is due to:

Which of the following is basic in nature?