Let $A = \begin{bmatrix} 1 & -1 & 1 \\ 2 & 1 & -3 \\ 1 & 1 & 1 \end{bmatrix}$ and $10B = \begin{bmatrix} 4 & 2 & 2 \\ -5 & 0 & \alpha \\ 1 & -2 & 3 \end{bmatrix}$. If $B$ is the inverse of matrix $A$,then $\alpha$ is:

Which of the following is a biofertilizer?

Two cells $A$ and $B$ are connected in the secondary circuit of a potentiometer one at a time,and the balancing lengths are $400 \ cm$ and $440 \ cm$ respectively. The emf of cell $A$ is $1.08 \ V$. The emf of the second cell $B$ in volts is:

Two coherent sources of intensity ratio $x^2$ interfere. In the interference pattern,which of the following relations is correct?

In the circuit,if the forward voltage drop for the diode is $0.5 \, V$,the current will be........$mA$.

Five masses,each of $2 \, kg$,are placed on a horizontal circular disc that can rotate about a vertical axis passing through its centre. All the masses are equidistant from the axis at a distance of $10 \, cm$. The moment of inertia of the whole system (in $g \cdot cm^2$) is (Assume the disc has negligible mass).