IB DP Physics Mock Exam SL Paper 1A Set 2 - 2025 Syllabus

IB DP Physics Mock Exam SL Paper 1A Set 2

Prepare for the IB DP Physics Mock Exam SL Paper 1A Set 2 with our comprehensive mock exam set 2. Test your knowledge and understanding of key concepts with challenging questions covering all essential topics. Identify areas for improvement and boost your confidence for the real exam

IB DP Physics Mock Tests -All Sets

Question

Light passes through two parallel layers as shown in figure below. The refractive indices for light travelling between air and the media are \(n_{1}\) and \(n_{2}\). What is angle \(\theta\) in image below?

(A) \(31^{\circ}\)
(B) \(38^{\circ}\)
(C) \(53^{\circ}\)
(D) \(73^{\circ}\)

▶️ Answer/Explanation

Detailed solution

1. Apply Snell’s Law at the Interface:
\(n_1 \sin \theta_1 = n_2 \sin \theta_2\)
Here, medium 1 is the bottom layer and medium 2 is the top layer.

\(n_1 = 5/3\)
\(\theta_1 = 50^{\circ}\) (angle of incidence with normal)
\(n_2 = 4/3\)
\(\theta_2 = \theta\) (angle of refraction)

2. Set up Equation:
\(\frac{5}{3} \sin 50^{\circ} = \frac{4}{3} \sin \theta\)

3. Solve:
Cancel the \(/3\):
\(5 \sin 50^{\circ} = 4 \sin \theta\)
\(\sin \theta = \frac{5}{4} \sin 50^{\circ}\)
\(\sin \theta \approx 1.25 \times 0.766 = 0.9575\)
\(\theta = \arcsin(0.9575) \approx 73.2^{\circ}\).
✅ Answer: (C)

Question

A circular coil lies in the plane of the page and is placed in a uniform magnetic field directed into the page. Negative charge carriers move around the coil in a counter-clockwise direction. What magnetic effect does this produce on the coil?

(A) The coil will rotate clockwise in the plane of the paper.
(B) The coil will rotate counter-clockwise in the plane of the paper.
(C) The diameter of the coil will tend to increase.
(D) The diameter of the coil will tend to decrease.

▶️ Answer/Explanation

Detailed solution

1. Determine Conventional Current:
Negative charge carriers (electrons) move counter-clockwise. Conventional current is defined as the direction of positive charge flow, so it is clockwise.

2. Apply the Motor (Left-Hand) Rule:

Magnetic field (B): Into the page.
Current (I): Clockwise.
- Top of the loop (current to the right): force acts upward.
- Bottom of the loop (current to the left): force acts downward.
- Left side of the loop (current upward): force acts to the left.
- Right side of the loop (current downward): force acts to the right.

3. Conclusion:
The magnetic forces act radially outward on all sections of the coil. As a result, the coil tends to expand and its diameter increases.
✅ Answer: (C)

Question

Which of below is a suitable material for use as a moderator in a nuclear reactor

(A) cadmium.
(B) concrete.
(C) uranium-238.
(D) water.

▶️ Answer/Explanation

Detailed solution

1. Function of Moderator:
A moderator slows down fast neutrons to thermal energies to facilitate fission.

2. Evaluate Materials:

(A) Cadmium: Used for control rods (absorbs neutrons).
(B) Concrete: Used for shielding.
(C) Uranium-238: Fuel.
(D) Water: Often graphite or water (heavy or light) is used as a moderator because hydrogen atoms have similar mass to neutrons, maximizing energy transfer during collisions.

✅ Answer: (D)

IB DP Physics Mock Exam SL Paper 1A Set 2 - 2025 Syllabus