Question

What was the original scientific basis for defining one second?

विकल्प

• Pendulum swings

• Light travel time

• 1/86,400 of a solar day

• Part of Earth’s orbit

Answer 1

1/86,400 of a solar day

Reason:

Originally, one second was defined as 1/86,400 of the average solar day, the time Earth takes to rotate once.