Which of the following descriptions of the image formed by a plane mirror is not correct. the image is----

The efficiency of a wheel and axle is 100% and the ratio of their radii is 5:1. calculate the effort required to lift a load of mass 20kg using this machine, [g = 10 m s\(^{-2}\)]

A freely suspended compass needle on the earth's surface settles in a plane called----------

An object is placed at different distances, u, from a converging lens of focal length, 15.0cm. For what value of u does the lens act as a microscope?

The periodic rise and fall in the intensity of sound produced whn two notes of nearly equal frequencies are sounded together is called?