Question

10. It requires 20 turns of the stem of a watch to wind the main spring and this stores sufficient energy to
he watch running for 30 h. If 10 turns are given to the stem, the watch will run for :
(a) 20 h
(b) 15 h
(c) 7.5 h
(d) 3.75 h​

Answer 1

Answer:

Explanation:

Let the compression in spring per turn be x

∴ For 20 turns energy stored =12k(20x)2

For 10 turns energy stored =12k(10x)2