Q.

To find the spring constant (k) of a spring experimentally, a student commits 2% positive error in the measurement of time and 1% negative error in measurement of mass. The percentage error in determining value of k is:                                    [2024]

1 3%  
2 4%  
3 5%  
4 1%  

Ans.

(1)  

        T=2πmk⇒k=4π2·mT2

        ∆kk=∆mm+2·∆TT⇒∆kk%=∆mm%+2∆TT%

        (We always take maximum error)

        ∆kk%=(-1)%+2(2)%=|-3%|=3%