Which of the following compounds is soluble in benzene but almost insoluble in water?

This is the only type of pollination which during pollination brings genetically different types of pollen grains to the stigma.

Given that the slope of the tangent to a curve $y = y(x)$ at any point $(x, y)$ is $\frac{2y}{x^2}$. If the curve passes through the centre of the circle $x^2 + y^2 - 2x - 2y = 0$,then its equation is

Water is conveyed through a uniform tube of $8 \text{ cm}$ in diameter and $3140 \text{ m}$ in length at the rate of $2 \times 10^{-3} \text{ m}^3/\text{s}$. The pressure required to maintain the flow is (Viscosity of water $= 10^{-3} \text{ SI units}$):

$A$ cylindrical metallic rod,in thermal contact with two heat reservoirs at its two ends,conducts an amount of heat $Q$ in time $t$. The metallic rod is melted and the material is formed into a rod of half the radius of the original rod. The amount of heat conducted by the new rod,when placed in thermal contact with the same two reservoirs in time $t$,is:

If $y = \sec(\tan^{-1} x)$,then $\frac{dy}{dx}$ at $x = 1$ is equal to