Question

There are atomic (Caesium) clocks capable of measuring time with an accuracy of 1 part in ${10}^{11}$. If two such clocks are operated to precision, then after running for 5000 years, these will record a difference of :

• A. $1day$
• B. $1s$
• C. ${10}^{11}s$
• D. $1year$

Answer 1

The correct option is B $1s$

$5000yrs$ $=5000\times 365\times 24\times 3600s$ = $1.5\times {10}^{11}s$
Since accuracy is $1$ part in ${10}^{11}$ s, the difference will be of $1s$.