Question

Define 1 ns.
A. \[{10^{ - 9}}\]s of Kr–clock of 1650763.73 oscillations
B. \[{10^{ - 9}}\]s of Kr–clock of 6521389.63 oscillations
C. \[{10^{ - 9}}\]s of Cs–clock of 1650763.73 oscillations
D. \[{10^{ - 9}}\]s of Cs–clock of 9192631770 oscillations

Answer 1

Hint: In this question, we need to define 1 nanosecond. The second is the specified time unit. The Cesium 133 atom is the most often utilized component in atomic clocks. Its transformation or resonant frequencies are extremely dependable and accurate. As a result, it can be used to describe a second.

Complete step by step solution:
Here, we can say that the unit of second was originally created depending on the rotation of the Earth; the Earth revolves on its axis once per day, and a second is derived as the \[\dfrac{1}{{86400}}\] th part of a day. However, due to irregularities in the frequency of the Earth's rotation, using Earth's rotation to define time is impractical.

As a result of the consistent frequency of microwave radiation it produces, Cesium-133 is used to define one second. The atomic shift of the cesium 133 atoms emits light or radiant energy in the form of microwaves at a highly specific frequency. A second is reported to have transpired when exactly 9,192,631,770 cycles or phases of this electromagnetic wave are observed. Hence, 1 ns is equal to \[{10^{ - 9}}\] s of Cs–clock of 9192631770 oscillations.

Therefore, the correct option is (D) .

Note:Highly specific clocks have a wide range of applications. The most significant is the Global Positioning System of the Earth (GPS). Exact distance measuring necessitates the use of atomic clocks. These clocks can provide a stable basis of comparison for scientific and technical applications such as detecting pulsar frequency fluctuations.