How is a voltmeter connected in a circuit?

How many electrons constitute a total charge of $1 \ C$?

Two wires of the same metal have the same length, but cross-sections are in the ratio $3 : 1$. They are joined in series. The resistance of the thicker wire is $10\, \Omega$. The total resistance of the combination will be:

Which of the following is true for a series combination of three resistors?

Which of the following materials has the highest number of free electrons?

$(a)$ State $Ohm's$ law. Express it mathematically.
$(b)$ Write symbols used in electric circuits to represent:
$(i)$ Variable resistance.
$(ii)$ Voltmeter.
$(c)$ An electric bulb is rated $220 \, V$ and $100 \, W$. When it is operated on $110 \, V$,what will be the power consumed?