Physics Past Questions and Answers

A string is fastened tightly between two walls 24cm apart. The wavelength of the second overtone is

A gas with initial volume of 2 X 10<sup style='font-size: smaller;'>-6</sup>m<sup style='font-size: smaller;'>3</sup> is allowed to expand to six times its initial value at constant pressure of 2 x 10<sup style='font-size: smaller;'>5</sup>Nm<sup style='font-size: smaller;'>-2</sup>. The work done is

A cell of internal resistance r supplies current to a 6.0Ω resistor and its efficiency is 75%. Find the value of r.

A resistance R is connected across the terminal of an electric cell of internal resistance 2Ω and the voltage was reduced to 3/5 of its nominal value.<br/>The value of R is

A student is at a height 4m above the ground during a thunderstorm. Give that the potential difference between the thundercloud and the ground is 10<sup style='font-size: smaller;'>7</sup>v, the electric field created by the storm is