A microscope is focused on a mark on a table, when the mark is covered by a plate of glass 2m thick, the microscope has to be raised 0.67cm for the mark to be once more in focus. Calculate the refractive index.

Radio waves belongs to the class of waves whose velocity is about

A single force which produces the same effect as a set of forces acting together at a point is known as the

Which of the following statement about the electromagnet shown above is correct?

Calculate the velocity ratio of a screw jack of pitch 0.2cm if the length of the tommy bar is 23cm