Question

जब R प्रतिरोध का एक तार तनित किया जाता है और इसकी त्रिज्या r/2 हो जाती है तो इसका प्रतिरोध कितना होगा?​

Answer 1

Sorry, I don't know this answer

Answer 2

answer:

16 R is right answer.

Explanation:

Initial radius of wire, r1 = r and final radius of wire, r2 = r/2 = 0.5r.

Since volume of the wire after stretch remains constant, therefore L1A1 = L2A2.

l1/l2 = A2/A1 = R2 square/R1 square =(0.5r/r) square = 1/4 ....

Therefore, R1/R2= L1/ L2×A2/A1 = 1/4×1/4 =1/16

R2=16R1

(so 16R answer.)