Two thin lenses of focal lengths $f_1$ and $f_2$ are in contact and coaxial. The power of the combination is

The potential energy of a diatomic molecule is given by $U = \frac{A}{r^{12}} - \frac{B}{r^6}$,where $A$ and $B$ are positive constants. The distance $r$ between them at equilibrium is:

If $E, M, J$ and $G$ respectively denote energy,mass,angular momentum,and universal gravitational constant,the quantity which has the same dimensions as the dimensions of $\frac{E J^2}{M^5 G^2}$ is:

The $emf$ of the cell $Ag | Ag^{+}(0.1 \, M) || Ag^{+}(1 \, M) | Ag$ at $298 \, K$ is ............ $V$.

The first operation involved in a Carnot cycle is

Distinguish between intracellular and extracellular digestion.