36 practice MCQs on magnetic fields, forces on charges, electromagnetic induction, AC circuits, generators and transformers. Every question has the correct answer and an explanation.
Start free — 20 questionsElectromagnetism and Electromagnetic Induction is part of the MDCAT Physics syllabus. This page collects Electromagnetism and Electromagnetic Induction MCQs in the style of past MDCAT papers — below are 12 of them with answers and explanations, and the full set of 36 questions is in the HighYield MDCAT QBank.
This chapter covers: magnetic fields, forces on charges, electromagnetic induction, AC circuits, generators and transformers.
Correct answer: C. 4.9 m
Using the efflux speed formula v = √(2gh), solving for height with v = 9.8 m/s and g = 9.8 m/s² gives h = v²/(2g) = 4.9 m.
Correct answer: B. Wbm-2
Magnetic field strength (flux density) is measured in Weber per square metre (Wb/m²), equivalent to the Tesla.
Correct answer: A. Conservation of energy
A transformer works on the principle of mutual induction, where a changing current in the primary coil induces an EMF in the secondary coil.
Correct answer: A. Visible Region
The Balmer series of hydrogen's emission spectrum lies within the visible region of the electromagnetic spectrum.
Correct answer: D. Flux is independent of shape
The magnetic flux through a surface depends on the magnetic field strength and the angle between the magnetic field lines and the surface. The shape of the surface does not directly affect the magnetic flux. The magnetic flux through a surface is given by the formula: Φ = BAcosθ In this case, both surfaces have the same area (1m²). Assuming the magnetic field strength and the angle θ are the same for both surfaces, the magnetic flux will be the same regardless of the shape of the surface. Therefore, the magnetic flux is independent of the shape of the surface.
Correct answer: B. Electrical, magnetically
In a transformer, there is no electrical connection between the two coils, which are typically referred to as the primary and secondary coils. However, they are magnetically linked due to the shared magnetic core. The primary coil is connected to an alternating current (AC) power source, which creates a changing magnetic field in the core. This changing magnetic field induces a voltage in the secondary coil through electromagnetic induction, allowing for the transfer of electrical energy from the primary to the secondary coil without a direct electrical connection
Correct answer: D. The magnetic field is strongest when the lines are farthest.
Option D is Incorrect because the magnetic field is strongest where the lines are closest together, indicating a higher field strength. The following statement is incorrect for any magnetic field lines.
Correct answer: B. 0.5 W
W=2.0N×1.0m=2.0JNext, the time taken to lift the weight is 4 seconds. Now we can find the power:P =work/time=2/4=0.5Watt
Correct answer: A. 0° and 180°
The magnitude of magnetic flux (Φ) through a surface is given by the formula Φ = B·A·cos(θ), where B is the magnetic field strength, A is the area, and θ is the angle between the magnetic field and the normal to the surface. For angles of 0° and 180°, cos(0°) = 1 and cos(180°) = -1, indicating that the magnitude of the flux remains the same, although the direction is opposite.In contrast, at 90°, the flux becomes zero because the angle leads to cos(90°) = 0. Similarly, at 270°, the flux is also zero due to the same cosine factor. Thus, options B, C, and D are incorrect as they do not yield the same non-zero flux values as found at 0° and 180°.
Correct answer: C. speed of light
Accelerating electromagnetic charges, such as electrons, radiate electromagnetic waves, which are a combination of electric and magnetic fields. These waves propagate through the electromagnetic field at a constant speed, which is:c = 299,792,458 meters per second (m/s)This speed is known as the speed of light, and it is a fundamental constant of the universe
Correct answer: B. electricity
The ability to produce an electromotive force (EMF) by changing the magnetic field inside a coil is the principle behind electromagnetic induction, which is used to generate electricity. This is the basis for many electric generators, including power plants, dynamos, and transformers.When the magnetic field inside a coil changes, an electric current is induced in the coil. This is known as electromagnetic induction. The changing magnetic field can be achieved by:- Moving a magnet near the coil- Rotating the coil within a magnetic field- Changing the current in a nearby coil
Correct answer: A. c=3 x 108 m/s
The speed of electromagnetic waves in free space (the speed of light) is c = 3×10⁸ m/s.
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