last science test

What is potential difference?

The work done per unit positive charge. Formula: V = W/q.

What is current?

The rate of flow of charge. Formula: I = q/t.

What is Ohm’s Law?

Current through a conductor is directly proportional to the potential difference across the conductor at constant temperature.

What is resistance?

A material’s opposition to the flow of electric current.

What is EMF (Electromotive Force)?

The total energy supplied per coulomb of charge by the cell.

What is magnetic flux density (B)?

A representation of the magnitude and direction of the magnetic field.

What is magnetic flux linkage?

The product of the number of turns on the coil and the flux through the coil. Formula: NΦ.

What is Faraday’s Law of Electromagnetic Induction?

The induced emf is directly proportional to the rate of change of magnetic flux (flux linkage). Formula: emf = −NΔΦ/Δt.

What is Lenz’s Law?

The induced current flows in a direction so as to set up a magnetic field to oppose the change in magnetic flux.

What is a diode?

A component that only allows current to flow in one direction.

What is threshold (cut-off) frequency (f₀)?

The minimum frequency of incident radiation at which electrons will be emitted from a particular metal.

What is work function (W₀)?

The minimum amount of energy needed to emit an electron from the surface of a metal; the work function is material specific.