Physics Flashcards

What is the SI unit of electric potential?

Answer: Volt

The SI unit of electric potential is the volt (V), defined as one joule per coulomb (1 V = 1 J/C). It represents the energy per unit charge.

In a nuclear reaction, what does the equation E = mc² represent?

Answer: The energy equivalent of mass, showing that mass and energy are interchangeable

Einstein's mass-energy equivalence shows that mass can be converted to energy and vice versa. In nuclear reactions, the mass defect is converted to energy according to E = mc².

What is the work-energy theorem as applied in Singapore A-Level Physics?

Answer: The net work done on a body equals the change in its kinetic energy

The work-energy theorem states that the net work done by all forces on a body equals the change in its kinetic energy: W_net = ΔKE = ½mv² - ½mu².

What is Faraday's law of electromagnetic induction?

Answer: The induced EMF is equal to the rate of change of magnetic flux linkage

Faraday's law states that the magnitude of the induced EMF equals the rate of change of magnetic flux linkage: EMF = -dΦ/dt. The negative sign (Lenz's law) indicates the direction opposes the change.

What happens to the resistance of a metallic conductor as its temperature increases?

Answer: Resistance increases because increased thermal vibrations impede electron flow

In metals, higher temperature causes greater lattice vibrations, which increase collisions with conduction electrons, thus increasing resistance. This is why metals have a positive temperature coefficient of resistance.

What is the difference between a stationary wave and a progressive wave?

Answer: Stationary waves do not transfer energy; progressive waves transfer energy in the direction of travel

A stationary wave is formed by the superposition of two identical progressive waves travelling in opposite directions. Unlike progressive waves, stationary waves do not transfer energy — they have fixed nodes and antinodes.