Question

One end of a horizontal thick copper wire of length 2L and radius 2R is welded to an end of another horizontal thin copper wire of length L and radius R. When the arrangement is stretched by applying forces at two ends, the ration of the elongation in the thin wire to that in the thick wire is

• A. 4.00
• B. 0.50
• C. 0.25
• D. 2.00

Answer 1

The correct option is D 2.00

For will be same
Now, $l=\frac{FL}{AY}\frac{l_1}{l_2}=\frac{L}{R^2}\times \frac{(2R{)}^2}{2L}=2$