Question

Atomic standard of time is based on periodic vibrations produced in-
1. Gold atom
2. Caesium atom
3. Silver atom
4. Uranium atom
5.

Answer 1

Correct Answer - Option 2 : Caesium atom

CONCEPT:

• Atomic standard of time forms the basis of caesium clock, also called the atomic clock.
  • It is based on periodic vibrations produced in caesium-133 atoms.
• Periodic vibrations: Periodic vibrations are the back and forth motion of particles or medium when displaced from their equilibrium position.

EXPLANATION:

• Atomic standard of time is based on periodic vibrations produced in caesium-133 atoms.
• Hence option 2 is correct.

• 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 × 10-15, e., one part in 10​-15.
  • Cesium atomic clocks provide very high accuracy.