Question

A child has drawn the electric circuit to study Ohm’s law as shown in the figure. His teacher told that the circuit diagram needs correction. Study the circuit diagram and redraw it after making all corrections.

Answer 1

You could firstly give a brief explanation about Ohm’s law. Then, you could explain how this experiment to Ohm’s law is done by clearly explaining the parameters whose reading is noted. You should also have a basic idea of what apparatus is used in measuring current and voltage. Then you could find the answer.

Complete answer:
In the question we are given a circuit as connected by a child whose intention was to perform an experiment so as to prove Ohm’s law. We are also told that his teacher found fault in this arrangement and we are supposed to find the same and correct and hence redraw the circuit.
Let us recall what Ohm’s law is. Ohm’s law states that Voltage across any two points is directly proportional to the current flowing through them. That is,
$V\alpha I$
$V=IR$
Where, R is the proportionality constant called resistance which is defined as the opposition offered to the flow of current.
So in order to prove ohm’s law, we have to note down variation of voltage with current and then should find their ratio to be a constant.
So we have to find the voltage across the resistor and hence voltmeter should be connected parallel to it and ammeter should be connected in series with it. So the correct circuit would be,

Note:
Potential difference by definition is the difference in potential between two points and so in order to measure the voltage across any element, we connect the voltmeter parallel to that element. Ammeter which is used to measure the current flowing through a particular element is connected in series with it.