JEE Main 2022 · 29 Jul · Shift 2 · Physics Q35

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PhysicsSingle correct+4 / -1Question 35 of 90

A 1 m long wire is broken into two unequal parts X and Y. The X part of the wire is streched into another wire W. Length of W is twice the length of X and the resistance of W is twice that of Y. Find the ratio of length of X and Y.

1:4

1:2

4:1

2:1

Answer and worked solution

Official answer: B

Stretching to twice the length halves the area, so $R_W=4R_X\propto4L_X$ . With $R_W=2R_Y$ : $4L_X=2L_Y$ , so $L_X:L_Y=1:2$ .

(B)

Topics:Ohm's law and resistivity

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JEE Main 2022 · 29 Jul · Shift 2, Physics question 35