Question

Which of the following gives the most accurate measurement of time?

• A. water clock
• B. atomic clock
• C. pendulum clock
• D. quartz clock

Answer 1

The correct option is B

atomic clock

Correct answer is option(B): atomic clock

Explanation for correct answer

1. An atomic clock is the most accurate instrument to measure the time.
2. It is based on characteristic frequencies of radiation emitted by certain atoms having a precision of about $1secondin300,000years.$
3. So, the precision of this clock is about $1sin1013s.$

Explanation for Incorrect answer:

1. Option(A):Water clock- In water clock, the rate of flow of liquid is used to measure the time.
2. Option(C): Pendulum clock: In pedulum we count number of oscillations made by bob attached to string
3. Option(D): Quartz clock: In quartz clock, number of oscillations made by quartz is counted to measure the time period.