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 and explain the photoelectric effect (6 marks)
An alpha particle is accelerated with 5MeV of kinetic energy towards the nucleus of a gold atom with atomic number 79. What is the distance of closest approach that is reached by the alpha particle?
Why is an object that moves in a circular path accelerating when it has constant speed?
What are quarks?