If three bulbs $60\,W$,$100\,W$ and $200\,W$ are connected in parallel,then

The potential difference between the points $P$ and $Q$ in the electric circuit shown is ................. $V$.

In how much time will one litre of ${H_2}$ be collected by a $5\, A$ current? (Given: $Z = 1 \times {10^{ - 8}}\,kg/C$ and density of ${H_2} = 0.09\,kg/{m^3}$)

In the figure,the value of the resistor to be connected between $C$ and $D$ so that the equivalent resistance of the entire circuit between $A$ and $B$ does not change with the number of elementary sets used is

$A$ current of $6 \ A$ enters one corner $P$ of an equilateral triangle $PQR$ having three wires of resistance $2 \ \Omega$ each and leaves by the corner $R$ as shown in the figure. Then the currents $I_1$ and $I_2$ are respectively:

$A$ battery has an $e.m.f.$ of $4 \ V$ and an internal resistance of $r$. When the battery is connected to an external resistance of $2 \ \Omega$,a current of $1 \ A$ flows through the circuit. If the terminals of the battery are short-circuited (connected directly),what will be the current in $A$ flowing through it?