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 ▸

Explain how a standing wave is formed


a solar cell of area 2m^2 has maximum a power output per unit area of 20W/m^2 . if four solar cells are used together at once, how much energy is release in 2 mins at max power output?


An electron falling from one energy level to another emits a photon of wavelength 550nm. What is the difference between the two energy levels?


What are the differences between standing waves and progressive waves?