Which one of the following pairs of gases are the major cause of 'Greenhouse effect'?

$\lim _{x \rightarrow \infty}\left(\frac{x+5}{x+2}\right)^{x+3}$ equals

At what speed should a source of sound move so that a stationary observer finds the apparent frequency equal to half of the original frequency?

$A$ load of $1 ~kg$ weight is attached to one end of a steel wire of area of cross-section $3 ~mm^2$ and Young's modulus $10^{11} ~N/m^2$. The other end is suspended vertically from a hook on a wall,then the load is pulled horizontally and released. When the load passes through its lowest position,the fractional change in length is $(g = 10 ~m/s^2)$.

The equation of the plane passing through $(1, 1, 1)$ and $(1, -1, -1)$ and perpendicular to $2x - y + z + 5 = 0$ is

In the circuit element given here,if the potential at point $B$,$V_B = 0$,then the potentials of $A$ and $D$ are given as