Physics Questions and Answers

Answer: A

The boiling point increases with pressure.

A liquid boils when its saturated vapour pressure equals the surrounding pressure, so a higher external pressure requires a higher temperature to reach it. A pressure cooker exploits this, raising the boiling point to about 120 °C; on a mountain, the lower pressure makes water boil below 100.

Answer: B

Electronegativity is a measure of non-metallic character.

It is the tendency of an atom to attract a shared pair of electrons towards itself, and it rises across a period and falls down a group - exactly the trend of non-metallic character. Metals are electropositive, giving electrons up rather than attracting them.

Answer: A

Newton's first law is the law of inertia.

It states that a body remains at rest or in uniform motion in a straight line unless an external force acts on it, so it defines inertia and identifies the inertial frames in which the other two laws hold.

Answer: C

Earthquake magnitude is measured on the Richter scale.

Devised by Charles Richter in 1935, it is logarithmic: each whole number is a tenfold rise in wave amplitude and about a thirty-twofold rise in energy released. The Mercalli scale, by contrast, records the intensity of the shaking felt at a place rather than the energy at the source.