Question

One second is defined as
a) 1650763.73 periods of krypton clock
b) 652189.6 periods of krypton clock
c) 1650763.73 periods of cesium clock
d) 9192631770 periods of cesium clock

Answer 1

The mechanism of atomic clocks is as follows:
When the subatomic particles called electrons, that orbit an atom's nucleus, are exposed to certain frequencies of radiation (such as radio waves) will jump forward and backward between the energy levels of an atom. This jumping of electrons is used to design clocks, which help a precise method to count seconds. Those clocks are usually known as atomic clocks, which use radioactive atoms as a medium.

Complete step by step answer:
Inside a cesium atomic clock, cesium atoms resonate or jump after 9,192,631,770 cycles per second and change their energy state.
So, we can say that 1 second in a cesium clock is equal to 9,192,631,770 cycles or periods of cesium atoms.
Hence, option (d) is the correct answer.

Note: Atomic clocks are the most accurate devices to predict the time and frequency standards known, and are used as primary devices for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.