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 ▸What is Olbers' Paradox?
In a circuit with a thermistor and bulb, what happens to the brightness of the bulb as the temperature increases?
A source of green laser light has a wavelength of 560nm, what is its frequency? Give your answer to an appropriate number of significant figures and using the correct units.
Draw and describe the major points of a typical stress-strain graph for a metal.