Describe one technique you could use to measure the threshold voltage for LEDs.

A sensitive ammeter is placed in series with LED. With the increase in Voltage, measure the potential difference value when it starts conducting. Black-out and shaded vision tube is used to observe the voltage value when visible light is first observed as the voltage is increased.

MP

Related Physics A Level answers

All answers ▸

Describe the energy changes in the 4 stages of a bungee jump - at the top, in freefall, when the cord is stretching and at the bottom


How does circular motion work?


By referencing the magnetic field and the alternating potential difference explain how a cyclotron produces a beam of high speed particles.


A person swims from a depth of 0.50 m to a depth of 1.70 m below the surface of the sea. density of the sea water = 1030 kg/m^3 gravitational field strength = 9.8 N/kg Calculate the increase in pressure on the swimmer. Give the Unit.