Free Electrostatics MCQs with Answers
831 Electrostatics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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Read the Electrostatics notesFree MDCAT chapter notes with key terms831 questions · page 26 of 42
- A. 4000 J
- B. 4 J
- C. 0.4 J
- D. 2000 J
Explanation: The energy stored in a capacitor can be calculated using the formula E = 0.5 * C * V^2.
Correct answer: 0.4 J- A. Volt
- B. Ampere
- C. Coulomb
- D. Watt
Explanation: This is the correct answer. The unit of work per unit charge is the volt.
Correct answer: Volt- A. Ohm's law
- B. Gauss law
- C. Coulomb's law
- D. Lenz law
Explanation: Coulomb's law states that the magnitude of the electrostatic force (F) between two point charges (q1 and q2) is directly proportional to…
Correct answer: Coulomb's law- A. V=W/Q
- B. V=Q/W
- C. Q=W/V
- D. Q=V/W
Explanation: The potential difference (V) between two points is defined as the work (W) required to move a unit charge (Q) from one point to the other.
Correct answer: V=W/Q- A. The whole body of the bird sitting on the live wire is at the same potential and hence no current flows through the body
- B. The whole body of the bird sitting on the live wire is at zero potential and hence no current flows through the body
- C. Because the air medium between the live wire and the earth contains large numbers of charged particles
- D. Because the air medium between the live wire and the earth contains large number of electrons
Explanation: The whole body of the bird sitting on the live wire is at the same potential and hence no current flows through the body.When a bird…
Correct answer: The whole body of the bird sitting on the live wire is at the same potential and hence no current flows through the body- A. area of the plates
- B. distance between the plates
- C. dielectric between them
- D. All
Explanation: The capacitance (C) of a capacitor depends on three main factors:1. *Area of the plates (A)*: Increasing the area of the plates increases…
Correct answer: All- A. Watts
- B. Henry
- C. Farads
- D. Joules
Explanation: The SI unit of capacitance is the farad (F), which is defined as the capacitance of a capacitor that stores one coulomb of electric charge…
Correct answer: Farads- A. Volt
- B. Coulomb
- C. Ampere
- D. Ohm
Explanation: The SI unit of electric potential, also known as voltage, is the volt (V).
Correct answer: Volt- A. Medium
- B. Very large
- C. Very small
- D. Large
Explanation: Coulomb's law assumes point charges with negligible size for accurate force calculations
Correct answer: Very small- A. U
- B. U/2
- C. 4U
- D. 2U
Explanation: Energy in a parallel circuit is divided equally among identical capacitors.
Correct answer: U/2- A. Actual lines
- B. Imaginary lines
- C. Solid lines
- D. Always curve lines
Explanation: Imaginary lines Explanation: Electric field lines are a conceptual tool used to visualize the electric field.
Correct answer: Imaginary lines512. Two point charges, each of magnitude q, are separated by a distance 2d. At a point mid-way between:
- A. E=0,V=0
- B. E≠0,V=0
- C. E=0,V≠0
- D. E≠0,V≠0
Explanation: E=0,V≠0 Correct. The electric field at the midpoint cancels out because the two charges create fields in opposite directions.
Correct answer: E=0,V≠0- A. JC−2
- B. JC
- C. CN−1
- D. JC−1
Explanation: JC−1Explanation: Volt (V) is defined as the potential difference, which is work (energy) per unit charge.
Correct answer: JC−1- A. 25 percent
- B. 50 percent
- C. 63.3 percent
- D. 36.8 percent
Explanation: Explanation:During the discharge of an RC circuit, the charge on the capacitor decreases exponentially according to the formula: Q(t) =…
Correct answer: 36.8 percent- A. Electric current
- B. Electric energy
- C. Electric field strength
- D. Electric power
Explanation: Correct. Energy (W) is given by W=QV, where Q is charge and V is potential difference
Correct answer: Electric energy- A. Ceramic capacitor
- B. Air gap capacitor
- C. Variable electrolytic capacitor
- D. Silver capacitor
Explanation: Correct. Air gap capacitors have a variable capacitance, which can be adjusted by changing the separation between the plates.
Correct answer: Air gap capacitor- A. Proportional to d
- B. Inversely proportional to d2
- C. Independent of d
- D. Inversely proportional to d
Explanation: Inversely proportional to d Explanation: The electric field due to a long, straight charged conductor is inversely proportional to the…
Correct answer: Inversely proportional to d- A. Remain the same
- B. Be four times
- C. Be doubled
- D. Be halved
- E. Become zero
Explanation: The capacitance will be doubled when the dielectric slab is inserted. So option C is correct.
Correct answer: Be doubled- A. E' points towards increasing V
- B. E' points toward decreasing V
- C. E' is perpendicular to V
- D. E' is parallel to V
- E. E' is opposite to V
Explanation: The relation E = − dV / dr (or in vector form E = −∇V) shows how the electric field relates to electric potential.
Correct answer: E' points toward decreasing V- A. ε0 / σ
- B. 2σ/ε0
- C. σ/ε0
- D. σ/E
Explanation: The electric field intensity between two uniformly, oppositely charged parallel plates can be given by: σ/ε0 where σ is the surface charge…
Correct answer: σ/ε0