A charged particle is placed at rest in a uniform magnetic field. What happens to it?
Correct answer B. It stays at rest because no magnetic force acts on it
Subject / 480 questions
MDCAT ECAT Physics MCQs
Page 10 of MDCAT ECAT Physics multiple-choice questions with answers. Tap an option to check yourself.
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- Electromagnetic Induction 30
- Fluid Dynamics 30
- Electrostatics 30
- Electronics 30
- Electromagnetism 30
- Current Electricity 30
- Work and Energy 30
- Waves 30
- Vectors and Equilibrium 30
- Nuclear Physics 30
- Dawn of Modern Physics 30
- Thermodynamics 30
- Rotational and Circular Motion 30
- Atomic Spectra 30
- Alternating Current 30
- Force and Motion 30
According to Faraday’s law, the magnitude of the emf induced in a coil is proportional to ____.
Correct answer D. the rate of change of magnetic flux linkage
The flux through each turn of a 200-turn coil falls uniformly from 0.030 Wb to 0.010 Wb in 0.10 s. What is the magnitude of the induced emf?
Correct answer A. 40 V
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A straight conductor 0.50 m long moves at 4.0 m/s at right angles to a uniform magnetic field of 0.30 T. What emf is induced between its ends?
Correct answer D. 0.60 V
Lenz’s law is a direct consequence of the law of conservation of ____.
Correct answer A. energy
The north pole of a bar magnet is pushed towards one face of a closed coil. What magnetic pole is induced on that face of the coil?
Correct answer C. A north pole, which repels the approaching magnet
A strong magnet dropped down a vertical copper tube falls much more slowly than in free fall. What is the reason?
Correct answer D. Eddy currents induced in the tube create a field opposing the magnet's motion
For a charged particle moving in a circle in a uniform magnetic field, the time for one revolution ____.
Correct answer C. does not depend on the particle's speed
An electron moves in a circle in a uniform magnetic field of 1.0 × 10⁻³ T. Take mₑ = 9.11 × 10⁻³¹ kg, e = 1.6 × 10⁻¹⁹ C. What is its period of revolution?
Correct answer C. 3.6 × 10⁻⁸ s
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An electron and a proton enter the same uniform magnetic field with equal velocities perpendicular to the field. Which statement is correct?
Correct answer A. They curve in opposite directions and the electron's circle is smaller
An alpha particle and a proton move with the same speed perpendicular to the same uniform magnetic field. Take the alpha particle’s mass as 4 times and its charge as 2 times that of the proton. What is the ratio of the radius of the alpha particle’s path to that of the proton?
Correct answer D. 2
A straight wire 0.25 m long carries a current of 4.0 A at right angles to a uniform magnetic field of 0.60 T. What force acts on the wire?
Correct answer C. 0.60 N
At what angle to a uniform magnetic field should a current-carrying straight wire be placed to experience the greatest force?
Correct answer D. 90°
In a velocity selector, crossed electric and magnetic fields of 3.0 × 10⁴ V/m and 0.20 T act on a beam of ions. At what speed do ions pass through undeflected?
Correct answer A. 1.5 × 10⁵ m/s
A charged particle moves parallel to a uniform magnetic field. What magnetic force acts on it?
Correct answer C. Zero
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Why does a uniform magnetic field do no work on a moving charged particle?
Correct answer A. The magnetic force is always perpendicular to the velocity
A proton moves at 2.0 × 10⁶ m/s at right angles to a uniform magnetic field of 0.50 T. Take e = 1.6 × 10⁻¹⁹ C. What is the magnitude of the magnetic force on it?
Correct answer C. 1.6 × 10⁻¹³ N
An electron moves at 4.0 × 10⁵ m/s at 30° to a uniform magnetic field of 0.20 T. Take e = 1.6 × 10⁻¹⁹ C. What is the magnitude of the magnetic force on it?
Correct answer D. 6.4 × 10⁻¹⁵ N
A charged particle enters a uniform magnetic field with its velocity perpendicular to the field. What path does it follow?
Correct answer D. A circle
A charged particle enters a uniform magnetic field with its velocity at 45° to the field lines. What is the shape of its path?
Correct answer B. A helix