Question

Cesium atomic clocks are known for their accuracy. However even theses clocks show some uncertainty. The time lost or gained by cesium atomic clock in one year is- 
1. 24 μs
2. 35 μs
3. 30 μs
4. 32 μs
5.

Answer 1

Correct Answer - Option 4 : 32 μs

CONCEPT:

• To measure time, we use the atomic standard of time that is based on periodic vibrations produced in a cesium atom.
• Cesium clock: It is used at National Physical Laboratory, New Delhi to maintain the Indian standard of time.
  • It is also called the atomic clock.
  • The vibration of the cesium atom regulates the rate of the cesium atomic clock.
  • The uncertainty imparted in time realization is ± 1 × 10-15s, e., one part in 10​-15.
  • Cesium atomic clocks provide very high accuracy.
• Accuracy: The accuracy of measurement shows how close the measured value is to the true value of the quantity

EXPLANATION:

• The uncertainty imparted in time realization is ± 1 × 10-15s, e., one part in 10​-15. That means uncertainty gained over time by this clock is less than one part I'm 10¹⁵.

The number of days in a year =366. So the number of seconds in a year will be :

the number of days in a year × number of hours in a day × number of hours in an hour × number of seconds in a minute = 366 × 24 × 60 × 60 = 31622400 second. This is approximately 32 × 10²¹s

Time lost by cesium click in one year (t),

 \(\Rightarrow t= \frac{3.16 \times 10^{7}}{10^{15}}\approx \space 32\space \mu s \)

Hence option 4) is correct.