A potentiometer wire of length 1m and resistance 2Ω is connected in series with a variable resistance and 2V accumulator of negligible resistance. What must be the variable resistance so that the fall of electric potential across the wire is 1mV/cm?

Aform of energy that is reflected or emitted from objects in the form of electrical and magnetic waves that can travel through space. there are many forms of  electromagnetic  energy including gamma rays, x rays, ultraviolet radiation, visible light, infrared radiation, microwaves and radio waves.