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 7 of 42
121. Two similar charges each of one coulomb placed in air one meter apart repel each other with a force
- A. 9x I0⁹N
- B. 9.2x I0⁴N
- C. 9x I08N
- D. 9x I0⁷
Explanation: Force due to two charge is F=Kq1q2/r2. Where r is the distance between the charges and q1 and q2 are the magnitude of the charges.
Correct answer: 9x I0⁹N- A. Q,-Q
- B. Q,Q
- C. Q/2, -Q/2
- D. Q,0
Explanation: When a capacitor C has a charge Q, the actual charges on its plates are +Q and −Q.
Correct answer: Q,-Q- A. 3µF
- B. 4µF
- C. 9µF
- D. 6µF
Explanation: When capacitors are connected in series, the equivalent capacitance Ceq is given by: 1/ Ceq = 1/C1 + 1/C2 + ...
Correct answer: 6µF- A. zero
- B. 197e/(4 π εo r2 )
- C. 79e/4 π εo r2
- D. 79e2/(4 π εo r2 )
Explanation: The electric field strength E at the surface of a charged sphere can be calculated using the formula: E = kQ/r2 where:E is the electric…
Correct answer: 79e/4 π εo r2- A. Joints in human body
- B. spinal cord
- C. brain
- D. applied battery
Explanation: EEG measures the electrical potentials generated by the activity of neurons in the brain.
Correct answer: brain126. The large horizontal metal plates are separated by 4 mm. The lower plate is at a potential of -6V.
- A. +22V
- B. +10V
- C. -22V
- D. -10V
Explanation: Magnitude of electric field is given as E= -ΔV/ΔdHere, Δd= 4mm, ΔV= -6-(V) and E= 400Vm-1400=-(-6-(V))/0.004400 =(6+V)/).004So, V=-22V
Correct answer: -22V- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The electric field lines due to a negative charge uninfluenced by any external interferce are in the form a straight lines that are…
Correct answer: Option B- A. 2.5x 1 0-8 C
- B. 10³C
- C. 4 x 10^3C
- D. 10-3
Explanation: The charge Q on a capacitor can be calculated using the formula: Q = C.V Here, Q is the charge on the capacitor, C is the capacitance and…
Correct answer: 10-3- A. energy/farad
- B. energy/columb
- C. energy/voulme
- D. energy
Explanation: The expression represents the energy stored per unit volume in the electric field.
Correct answer: energy/voulme- A. series combination
- B. parallel combination
- C. both series and parallel combination
- D. none of these
Explanation: When capacitors are connected in parallel, the total or equivalent capacitance Ceq is the sum of the individual capacitances.
Correct answer: parallel combination131. If the distance between the plates of parallel plates condenser is increased, its potential will
- A. will remain same
- B. increase
- C. decrease
- D. decrease exponentially
Explanation: The electric potential is given as V = -E. d. Here E is the electric field and d is the distance between the plates.
Correct answer: increase- A. 6.2 x 10¹⁸
- B. 1.6 x 10¹⁹
- C. 6.2 x 10 ²¹
- D. 1.6 x 10-²⁷
Explanation: The electric potential is given as V = -E. d. Here E is the electric field and d is the distance between the plates.
Correct answer: 6.2 x 10¹⁸- A. electric field surrounding the capacity
- B. electric field inside the capacitor
- C. both a and b
- D. gravitational field
Explanation: In a charged capacitor, the energy primarily resides in the electric field inside the capacitor.
Correct answer: electric field inside the capacitor- A. 8µF
- B. 0.8µF
- C. 4µF
Explanation: When capacitors are connected in parallel, the total or equivalent capacitance Ceq is the sum of the individual capacitances.
Correct answer: 8µF- A. DC
- B. AC
- C. Both DC and AC
- D. rapidly fluctuating current
Explanation: Direct current (DC) cannot flow through a capacitor because a capacitor blocks the flow of steady-state currents.
Correct answer: DC- A. 200J
- B. 10J
- C. 10eV
- D. 100J
Explanation: We know that Work(W) = Electric potential(V). charge(Q)According to work energy principle W= ΔK.EK.E=V.Q = 0.10 X 1000 =100 J
Correct answer: 100J- A. 1 / 4 π εo .q/r
- B. 1 / 4 π εo .q/r2
- C. 4 π εo
- D. q/ εo
Explanation: According to gauss 's law electric flux through a surface due to a charge is 1/ εo time the charge enclosed (q) by the surface
Correct answer: q/ εo- A. σ/2 εo
- B. σ
- C. zero
- D. σ/ εo
Explanation: The electric field E1 due to the positive charge density (+σ) points away from that plate.
Correct answer: σ/ εo- A. an insulator
- B. negatively charged
- C. positively charged
- D. a conductor
Explanation: As, opposite charges repel leaves of a positively charged electroscope diverge when a positively charged object is brought closer.
Correct answer: positively charged- A. less than unity
- B. equal to unity
- C. greater than unity
- D. no hard and fast rule
Explanation: εr is called relative permittivity. It is the ratio of permittivity of a substance ε and the permittivity of free space εo.
Correct answer: greater than unity