QUESTION 1 MULTIPLE-CHOICE QUESTIONS Four possible options are provided as answers to the following questions - NSC Physical Sciences - Question 1 - 2017 - Paper 1

In an elastic collision, both momentum and kinetic energy are conserved. Thus, the correct answer is D Momentum is conserved; Kinetic energy is conserved.

The electrostatic force between two charges is given by Coulomb's Law: $F = k \frac{q_1 q_2}{r^2}$ If the force increases to 4F, the new distance must be reduced, so the correct answer is D r/2.

Using the potential divider rule, since Y has three times the resistance of X, the potential difference across the battery can be calculated as follows:

total resistance = R + 3R = 4R, so, V across battery = V × (R/4R) hence the answer is A 2V.

As the intensity of the incident light increases, the photocell produces more electrons, leading to a higher current on the ammeter. Therefore, the correct answer is A INTENSITY Increases; AMMETER READING Increases.

In this scenario, the forces acting on the ball include gravitational force (downward) and the normal force (perpendicular to the incline). The correct free-body diagram must reflect these forces accurately, leading to the correct choice indicating both forces.

The longer the time of impact, the smaller the force experienced by the driver as per the impulse-momentum theorem. Therefore, the answer is A increases, the net force will decrease.

The point P corresponds to the threshold frequency in the photoelectric effect, below which no electrons are emitted. Therefore, the correct answer is C threshold frequency.

Due to the Doppler effect, as the observer moves away from the sound source, the frequency of the wave heard decreases, resulting in a lower pitch. Thus, the answer is C frequency of the source appears to decrease.

An AC generator converts mechanical energy to electrical energy. The type of ring used in this process is known as a split-ring commutator. Therefore, the answer is C mechanical energy to electrical energy.