Q. The term “Kibble Balance” is often seen in news is related to which of the following?

[A] Device to measure Planck Constant.

[B] Device to measure heat balance.

[C] Device to measure water balance.

[D] Device to measure wind balance.

Answer: A

‘Kibble Balance’, is a device that was used to measure the Planck Constant and thereby reboot the kilogram.  

  • Named after its inventor, Bryan Kibble at the U.K.’s National Physical Laboratory (NPL), who conceptualized it in 1975, the Kibble balance is an exquisitely accurate weighing machine.  
  • Like any balance, it is designed to equalize one force with another: In this case, the weight of a test mass is exactly offset by a force produced when an electrical current is run through a coil of wire immersed in a surrounding magnetic field. 

Source: The Hindu