All Free Physics MCQs with Answers
Every Physics question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
13,934 questions · page 669 of 697
- A. 2.5m/s
- B. 24m/s
- C. 4.44m/s
- D. Cannot be calculated unless the area of the hole is given
Explanation: The problem can be solved using Torricelli's Theorem, which states that the speed of efflux, v, of a fluid under the force of gravity…
Correct answer: 24m/s13362. Which one of the following must be decreased in order to increase the capacitance of a capacitor?
- A. The area of the plates
- B. The distance between the plates
- C. The number of the plates
- D. The dielectric constant
Explanation: The formula for capacitance is C = εo εr A/d. Decreasing the distance between the plates would increase the capacitance since C is…
Correct answer: The distance between the plates- A. 6 volt
- B. 1 volt
- C. 3 volt
- D. 2 volt
Explanation: When capacitors are connected in series, the total capacitance (C_total) is given by the reciprocal of the sum of the reciprocals of the…
Correct answer: 6 volt- A. Relative permittivity
- B. Permittivity
- C. Permeability
- D. Electric polarization
Explanation: The ratio of the capacitance of the capacitor with a dielectric to the capacitance of the same capacitor with free space is given by the…
Correct answer: Relative permittivity- A. 1/2 CV2
- B. 1/2 QV
- C. 1/2 m v2
- D. Both A and B
Explanation: The correct answer is Option D: Both A and B. The energy stored in a charged capacitor can be represented by the formulas E = 1/2 CV² or E…
Correct answer: Both A and B- A. Be fully charged in 1 second by a current of 1 Ampere
- B. Store 1 coulomb of charge at potential difference of 1 volt
- C. Gain 1 joule of energy when 1 coulomb of charge is stored on it
- D. Discharge in 1 second when connected across a resistor of resistance 3 ohms
Explanation: A capacitance of 1F produces 1V of potential difference for an electric charge of one coulomb (1C).
Correct answer: Store 1 coulomb of charge at potential difference of 1 volt- A. E√10
- B. E/√10
- C. 10E
- D. E/10
Explanation: The relationship between the electric field in the absence of the dielectric (E0) and the electric field with the dielectric (E) is given…
Correct answer: E/10- A. 4x
- B. 2x
- C. x/2
- D. x/4
Explanation: C = A𝛆 / d where C is capacitance, 𝛆 is the permittivity of free space, A is the area of plates, and d is the distance between them.
Correct answer: x/2- A. 400 J
- B. 4 J
- C. 0.2 J
- D. 200 J
Explanation: The energy stored in a capacitor can be calculated using the formula U = 0.5 * Q * V, where U is the energy, Q is the charge, and V is the…
Correct answer: 200 J- A. 2 F
- B. 4 F
- C. 0.5 F
- D. 0.25 F
Explanation: The potential difference across the parallel plate capacitor is 10V- (-10)=20VCapacitance= Q/V = 40/20 = 2 FaradAs it is numerical, it can…
Correct answer: 2 F13371. When dielectric is removed from plates of a charged capacitor then electric field between plates:
- A. Remains unchanged
- B. Decreases
- C. Increases
- D. All of the above
Explanation: When the dielectric is removed from the plates of a charged capacitor, the electric field between the plates generally increases.
Correct answer: Increases- A. C - E
- B. E.C
- C. C + E
- D. C/E
Explanation: The capacitance of a parallel plate capacitor with a dielectric is given by the formula C = E * (ε₀ * A / d), where E is the dielectric…
Correct answer: C/E- A. 6
- B. 9
- C. 12
- D. 18
Explanation: When capacitors are connected in parallel, their equivalent capacitance is the sum of their individual capacitances.
Correct answer: 6- A. An electric field only
- B. A magnetic field only
- C. Both magnetic and electric field
- D. Magnetic and gravitational field
Explanation: Magnetic and gravitational field: This option is incorrect. A moving electric charge does not generate a gravitational field.
Correct answer: Both magnetic and electric field- A. proton
- B. electron
- C. both will suffer greater defection
- D. None of these
Explanation: The deflection is inversely proportional to mass, so for an electron and a proton moving with the same velocity, an electron with lighter…
Correct answer: electron- A. Kinetic energy
- B. Magnitude of velocity
- C. Direction of velocity
- D. All of these
Explanation: When a charged particle enters a uniform magnetic field, the magnetic force acts perpendicular to the velocity of the particle.
Correct answer: Direction of velocity- A. F = qvB
- B. F = qE
- C. F = 0
- D. F = mv2/r
Explanation: When a charged particle moves parallel to a magnetic field, the force acting on it is zero because the angle between the velocity and…
Correct answer: F = 0- A. Both electric and magnetic field
- B. Both magnetic and gravitational field
- C. A magnetic field only
- D. An electric field only
Explanation: The definition of magnetic field: The region where a moving charge particle experiences a force, provided that it moves perpendicular to…
Correct answer: A magnetic field only- A. Circle
- B. Helix
- C. Ellipse
- D. Straight line
Explanation: The charged particle has a velocity that is neither perpendicular nor parallel (along) to the magnetic field, i.e it is moving with an…
Correct answer: Helix- A. Of magnitude B/E and parallel to B
- B. Of magnitude E/B and parallel to B
- C. Of magnitude B/E and perpendicular to both ⃑E and ⃑B
- D. Of magnitude E/B and perpendicular to both ⃑E and ⃑B
Explanation: If velocity must remain constant, the net force must be zero, so electric and magnetic forces must be equal.magnetic force = electric…
Correct answer: Of magnitude E/B and perpendicular to both ⃑E and ⃑B