What is the product formed when phenol reacts with concentrated $HNO_3$?

$A$ person running horizontally observes that rain is falling on his head vertically with a speed of $10\,m/s$. When he stops,he observes that the rain is falling at an angle of $30^{\circ}$ with the vertical. Find the speed of the rain with respect to the ground.

The major product of the following reaction is:

An inductor and a resistor are connected in series to an $AC$ source of $10 \ V$. If the potential difference across the inductor is $6 \ V$,then the potential difference across the resistor is: (in $V$)

There are two holes,one each along the opposite sides of a wide rectangular tank. The cross-section of each hole is $0.01 ~m^2$ and the vertical distance between the holes is $1 ~m$. The tank is filled with water. The net force on the tank in newtons when the water flows out of the holes is (Density of water $= 1000 ~kg/m^3$,$g = 10 ~m/s^2$):

Which of the following is a bidentate ligand?