Which of the following instruments is used to measure the rate of transpiration in plants?

$A$ curve passes through the point $\left(1, \frac{\pi}{6}\right)$. Let the slope of the curve at each point $(x, y)$ be $\frac{y}{x}+\sec \left(\frac{y}{x}\right)$,where $x>0$. Then,the equation of the curve is:

Crystalline sodium chloride is an insulator of electricity because $......$

$A$ long solenoid of radius $2\, cm$ has $100\, turns/cm$ and carries a current of $5\, A$. $A$ coil of radius $1\, cm$ having $100\, turns$ and a total resistance of $20\, \Omega$ is placed inside the solenoid coaxially. The coil is connected to a galvanometer. If the current in the solenoid is reversed in direction,find the charge flown through the galvanometer.

Two identical parallel plate air capacitors are connected in series to a battery of emf $V$. If one of the capacitors is inserted in a liquid of dielectric constant $K$,then the potential difference of the other capacitor will become:

If two sides of a triangle are represented by $3x^2-5xy+2y^2=0$ and its orthocentre is $(2,1)$,then the equation of the third side is