JEE Main 2022 · 26 Jul · Shift 1 · Physics Q56

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PhysicsInteger+4 / -1Question 56 of 90

Resistances are connected in a meter bridge circuit as shown in the figure. The balancing length $l_1$ is 40 cm. Now an unknown resistance $x$ is connected in series with P and new balancing length is found to be 80 cm measured from the same end. Then the value of $x$ will be ______ $\Omega$ .

Metre bridge AC with P = 4 Ω in the left gap and Q in the right gap, galvanometer G from B to the jockey J at l1 from A, cell E and key K across the wire.

Your answer

Answer and worked solution

Official answer: 20

Balance. $\frac PQ=\frac{40}{60}$ , $Q=6$ Ω. New. $\frac{4+x}6=\frac{80}{20}$ , $x=20$ Ω.

Answer: 20

Topics:Wheatstone bridge and metre bridge

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JEE Main 2022 · 26 Jul · Shift 1, Physics question 56