What will happen if you connect a voltmeter in series in an electric circuit?

A student, Vagisha set-up an electric circuit as shown in the figure to measure the current in the circuit and the potential difference across lamp, $L_1$. State if the lamps $L_1$ and $L_2$ are in parallel or in series.

A student, Vagisha set-up an electric circuit as shown in the figure to measure the current in the circuit and the potential difference across lamp, $L_1$.

What is(are) the mistake(s), if any, that Vagisha has made in setting up the circuit?

A student, Vagisha set-up an electric circuit as shown in the figure to measure the current in the circuit and the potential difference across lamp, $L_1$.

Correct the mistake(s), if any, that Vagisha has made and draw the correct circuit diagram.

In a television tube, a beam of electrons is emitted. If the beam current is given to be $40 \mathrm{\mu A}$, how many electrons strike the television screen each second? Also, calculate the total charge striking the television screen in $1$ minute. $[e = 1.6 \times {10}^{-19} \mathrm{C}]$

Four bulbs are to be lit from a battery in such a way that three bulbs are controlled by the same switch and the remaining fourth bulb is controlled by its own switch. Draw a circuit diagram to show how you will set-up the circuit.