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 ▸Two identical uniform spheres each of radius R are placed in contact. The gravitational force between them is F. They are then separated until the force between them is one ninth of the magnitude. What is the distance between the surfaces of the spheres?
A car undergoes uniform acceleration from a starting velocity of 10ms^-1 to 20ms^-1 in 10s. Assuming the car's mass is 2000kg, calculate the net force in the direction of the acceleration.
How to solve horizontally-launched projectile motion problems using equations of motion?
Why do skydivers have a terminal velocity?