Physics Past Questions and Answers

If the fraction of the atoms of a radioactive material left after 120years is 1/64, what is the half-life of the material?

A certain radioactive source emits radiations that were found to be deflected by both magnetic and electric fields. The radiations are

A 2H inductor has negligible resistance and is connected to a 50/Ï€ Hz A.C. Supply. The reactance of the inductor is

A cell of internal resistance 1Ω supplies current to an external resistor of 3Ω. The efficiency of the cell is

A conductor of length 2m carries a current of 0.8A while kept in a magnetic field of magnetic flux density 0.5T. The maximum force acting on it is