MCQ Collection
MDCAT 2026 MCQs
Practice MDCAT 2026 questions with answers and explanations.
Choose an option to check your answer.
A.
4 V
B.
25 V
C.
100 V
D.
500 V
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Correct Answer: C. 100 V
Explanation:
Voltage ratio equals turns ratio.
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A.
200
B.
600
C.
400
D.
800
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Correct Answer: C. 400
Explanation:
One half-life reduces the undecayed population by half.
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A.
Only continuous mechanical waves
B.
Massive charged particles
C.
Stationary electric fields
D.
Discrete packets of energy
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Correct Answer: D. Discrete packets of energy
Explanation:
A photon carries energy proportional to frequency.
Choose an option to check your answer.
A.
50
B.
200
C.
400
D.
100
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Correct Answer: D. 100
Explanation:
After three half-lives, the remaining fraction is (1/2)^3=1/8.
Choose an option to check your answer.
A.
Emission of electrons from a surface when light of sufficient frequency falls on it
B.
Production of light by heated metals only
C.
Deflection of electrons by a magnetic field
D.
Creation of neutrons by visible light
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Correct Answer: A. Emission of electrons from a surface when light of sufficient frequency falls on it
Explanation:
Photoelectric emission requires photon energy above the material's work function.
Choose an option to check your answer.
A.
1/4
B.
1/2
C.
1/3
D.
1/8
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Correct Answer: A. 1/4
Explanation:
Twelve hours equals two half-lives.
Choose an option to check your answer.
A.
Energy of every electron in the atom
B.
Minimum energy needed to remove an electron from its surface
C.
Maximum photon energy
D.
Energy stored in a capacitor
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Correct Answer: B. Minimum energy needed to remove an electron from its surface
Explanation:
The work function depends on the material and surface condition.
Choose an option to check your answer.
A.
Particles can never behave like waves
B.
Only photons have momentum
C.
Moving particles have an associated wavelength
D.
Mass and energy are unrelated
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Correct Answer: C. Moving particles have an associated wavelength
Explanation:
Matter waves link momentum with wavelength through λ=h/p.
Choose an option to check your answer.
A.
Any continuously variable electron energy
B.
The total mass of the atom
C.
The electric charge of the nucleus
D.
An allowed discrete energy state of an electron in an atom
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Correct Answer: D. An allowed discrete energy state of an electron in an atom
Explanation:
Bound atomic electrons occupy quantized energy states.
Choose an option to check your answer.
A.
Atoms of the same element with different numbers of neutrons
B.
Atoms with different proton numbers but equal masses
C.
Ions with different charges only
D.
Molecules with different structures
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Correct Answer: A. Atoms of the same element with different numbers of neutrons
Explanation:
Isotopes have the same atomic number and chemical identity.
Choose an option to check your answer.
A.
Chemical burning of atoms
B.
Spontaneous transformation of unstable nuclei with emission of radiation
C.
Forced ionization by heat only
D.
Reflection of electromagnetic waves
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Correct Answer: B. Spontaneous transformation of unstable nuclei with emission of radiation
Explanation:
Radioactive decay is a nuclear process.
Choose an option to check your answer.
A.
Time for all nuclei to decay
B.
Time for activity to double
C.
Time for half the radioactive nuclei in a sample to decay
D.
Time for one atom to emit two particles
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Correct Answer: C. Time for half the radioactive nuclei in a sample to decay
Explanation:
After each half-life, the number of undecayed nuclei halves.
