A student is provided with a variable voltage source V, a test resistor $\mathrm{R}_{\mathrm{r}}=10 \Omega$, two identical galvanometers $\mathrm{G}_{1}$ and $\mathrm{G}_{2}$ and two additional resistors, $\mathrm{R}_{1}=10 \mathrm{M} \Omega$ and $\mathrm{R}_{2}=0.001 \Omega$. For conducting an experiment to verify ohms law, the most suitable circuit is:

JEE Main · 2023 · 06 Apr 2023 · Shift 2 · Current Electricity

A student is provided with a variable voltage source V, a test resistor

R_{r} = 10Ω

, two identical galvanometers

G_{1}

and

G_{2}

and two additional resistors,

R_{1} = 10 M Ω

and

R_{2} = 0.001Ω

. For conducting an experiment to verify ohms law, the most suitable circuit is:

(A)(see structure)
(B)(see structure)
(C)(see structure)
✓ Correct
(D)(see structure)

Answer: (C)

Solution

To verify Ohm's law both the current through the test resistor and the voltage across it must be measured. A galvanometer becomes an ammeter when a small shunt is connected in parallel with it, so the galvanometer carrying

R_{2} = 0.001 Ω

across it forms the ammeter and must be placed in series with

R_{T}

. A galvanometer becomes a voltmeter when a large resistance is connected in series with it, so the galvanometer with

R_{1} = 10 M Ω

in series forms the voltmeter and must be connected across

R_{T}

. The suitable circuit is the one with the low-shunt ammeter in series and the high-resistance voltmeter in parallel with the test resistor.

JEE Main · 2023 · 06 Apr 2023 · Shift 2 · Single correct option

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JEE Main · 2023 · 06 Apr 2023 · Shift 2 · Current Electricity

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