A sentence has been given in Active/Passive Voice. Out of the four given alternatives, select the one which best expresses the same sentence in Passive/Active Voice.
A seconds pendulum is a pendulum whose period is precisely two seconds i.e, one second for a swing in one direction and one second for the return swing.
Out of the four alternatives, choose the one which can be substituted for the given words/sentences and click the button corresponding to it. An exact copy