Question : A and B are two wires. The radius of A is twice that of B. If they are stretched by the same load, then how much is the stress on B to that on A?
Doubt by Aanshika
Solution :
We know,
Stress = Force (Load) / Area
Stress = F/πr2
Stress ∝ 1/r2 [Force (Load) is same]
SA/SB = (rB)2/(rA)2
SA/SB = (rB/rA)2
SA/SB = (rB/2rB)2 [∵rA=2rB]
SA/SB = 1/4
4SA=SB OR SB=4SA