Measurement of Mass and Time — Prelims Questions

Which of the following statements about the SI unit of mass, the kilogram, is correct after its redefinition in 2019?

An atomic clock uses the transition between two hyperfine levels of the ground state of which atom to define the second?

A pendulum clock is taken from the Earth's surface to the top of a very high mountain. How will its time period be affected?

Which of the following instruments would be most suitable for measuring the mass of a subatomic particle?

If a clock loses 10 seconds per day, what is its percentage error in time measurement?

Which of the following statements best describes the concept of 'inertial mass'?