OCR A Level Physics RANDOM

What does the term 'number density' mean in the context of circuits?

• The number of atoms in a metal that can cause resistance

• The number of conduction electrons per unit volume

• The percentage of doping atoms added to a semiconductor

• The resistance multiplied by the area of a wire divided by its length

What is the total resistance here?

• 13Ω

• 2.8Ω

• 4.5Ω

• 6Ω

What would you use a potential divider equation for?

• To find the voltage across a resistor

• The find the EMF of a battery

• To find how the current splits in a circuit

• To compare two resistors in parallel

This is the IV Characteristics for which component?

• LDR

• Diode

• Resistor

• Bulb

A standing wave is set up on a string oscillating at the 3rd Harmonic. How many nodes will it have?

• 2

• 3

• 4

• 5

Light is passing from air into glass. Which of the following is NOT true?

• Some light will be reflected

• Total internal reflection might happen

• The angle of refraction will be smaller than the angle of incidence

• The light will move more slowly in the glass than in air

A wave has a period of 2s and three and a half waves cover a distance of 14m. What is the wavelength?

• 8ms^-1

• 28ms^-1

• 2ms^-1

• 7ms^-1

What does superposition of waves mean?

• Waves being restricted to oscillating in a single plane

• Two waves meeting and cancelling out

• Waves spreading out through a gap

• Two waves passing through a point and combining to form a single wave

Which of these statements about the photoelectric effect are true?

• Each photon can release up to 2 electrons from a metal

• The more photons the greater the kinetic energy of the electrons released

• The energy of the photons must exceed the work function of the metal for the electrons to be released

• Red light will release electrons with higher Kinetic Energy than Blue light

An electron jumps from the -3.5eV energy level to the -2.1eV energy level of an atom. What wavelength radiation would be needed for this to occur?

• 8.9 x 10^-7m

• 2.2 x 10^-6m

• 4.4 x 10^-7m

• 1.3 x 10^-6m