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 ▸A bullet is fired horizontally from a gun at a height of 1.5m at 280m/s. Calculate the time taken for it to hit the ground. A second bullet is fired from an adjacent gun at 370m/s. Calculate the distance it travel before the first bullet hits the ground.
How does one calculate centripetal force?
Describe the photoelectric effect.
How would you explain general relativity?