Which of the following has the lowest boiling point?

If the charge on the capacitor is increased by $2 \ C$,the energy stored in it increases by $21 \%$. The original charge on the capacitor is: (in $C$)

Root cap is absent in

The parabola with directrix $x+2y-1=0$ and focus $(1,0)$ is

Which of the following is not a fat-soluble vitamin?

In the circuit shown,the reading of the Ammeter is doubled after the switch is closed. Each resistor has a resistance $1\,\Omega$ and the ideal cell has an $e.m.f.$ $10\,V$. Then,the Ammeter has a coil resistance equal to ............ $\Omega$