A projection lantern is used to give the image of a slide on a screen. If the image is 24 times as large as the slide and the screen is 72.0m from the projecting lens, what is the position of the slide from the lens?

An electron of charge 1.6 x 10^-19C and mass 9.1 x 10^-31kg is accelerated between two metal plates with a velocity of 4 x 10⁷ms^-1, the potential difference between the plates is

A cell of internal resistance 0.01Ω can be measured accurately using the

What optical instrument can best be constructed with converging lenses of focal lengths 50cm and 5cm?

in a pure semiconductor, the number of electrons in the conduction band is