A-Level Physics 2

Question 1

What is the SI unit of electric potential?

Accepted Answer

Volt

Answer

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.

Question 2

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

Accepted Answer

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

Answer

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.

Question 3

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

Accepted Answer

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

Answer

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.

Question 4

What is Faraday's law of electromagnetic induction?

Accepted Answer

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

Answer

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.

Question 5

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

Accepted Answer

Resistance increases because increased thermal vibrations impede electron flow

Answer

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.

GCE A-Level Practice Test

GCE A-Level Practice Test

A-Level Physics 2