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 692 of 697
- A. 10 cm
- B. 30 cm
- C. 40 cm
- D. 120 cm
Explanation: The correct answer is 40 cm. For a string fixed at one end and free at the other, the second harmonic corresponds to one full wavelength…
Correct answer: 40 cm- A. Identical
- B. Different
- C. Any of Option A or B
- D. Stationary waves cannot be formed
Explanation: Stationary waves, or standing waves, are formed when two waves of the same amplitude and frequency travel in opposite directions along the…
Correct answer: Identical- A. 2 Hz
- B. 4 Hz
- C. 5 Hz
- D. 10 Hz
Explanation: (Remember that node to node is half A) so λ= 10/5 and then λ = 2x2=4mThen we find out the frequency using the formula v = fλ ie 20 = f(4)…
Correct answer: 5 Hz13824. What is the current in a 2 x 10^6 ohms resistor having a potential difference of 6 x 10^-3 volts?
- A. 1 x 10^-3 A
- B. 2 x 10^-3 A
- C. 3 x 10^-3 A
- D. 4 x 10^-3 A
Explanation: We know according to ohm's law.V=IRI = V/RPutting valuesWe get answer3×10-3 A
Correct answer: 3 x 10^-3 A13825. What is the current in a 2 x 10^6 ohms resistor having a potential difference of 6 x 10^3 volts?
- A. 1 x 10^-3 A
- B. 2 x 10^-3 A
- C. 3 x 10^-3 A
- D. 4 x 10^-3
Explanation: According to Ohm's Law V=IR Since V= 6x103 Volts R= 2 x 106 ohms Hence; I=V/R; I = 6x103 / 2x106 = 3x10-3 Ampere (so option C is the…
Correct answer: 3 x 10^-3 A- A. One ampere
- B. Two ampere
- C. 1.6x 10+19 amperes
- D. 1.6 x 10^-19 amperes
Explanation: I = Q/t = Ne/t = 2 x 1.6 x 10-19 / 2 = 1.6 x 10-19 A. Therefore, D is the correct answer.
Correct answer: 1.6 x 10^-19 amperes- A. Kirchholf's 1st law
- B. Wheatstone bridge
- C. Combination of resistance
- D. Kirchholf's 2nd law
Explanation: Wheatstone Bridge: The Wheatstone bridge is a circuit arrangement consisting of four resistive elements connected in a diamond shape.
Correct answer: Wheatstone bridge13828. Ampere hour is a unit of:
- A. Current
- B. Time
- C. Quantity of charge
- D. Power
Explanation: Quantity of charge: This option is correct. Ampere hour is a unit of the quantity of charge, representing the total charge transported by…
Correct answer: Quantity of charge- A. Same current
- B. Same power
- C. Different potential and same current
- D. Same potential difference
Explanation: In a parallel circuit, each appliance is connected directly to the main line and the neutral line, creating individual pathways for the…
Correct answer: Same potential difference- A. voltage of battery
- B. power of battery
- C. e.m.f of battery
- D. all of these
Explanation: EMF is the source of voltage in a battery responsible for flow of charges through a circuit.
Correct answer: e.m.f of battery- A. 3.21 × 10^18
- B. 2.2 × 10^16
- C. 1.602 × 10^19
- D. 6.42 × 10^18
Explanation: To find the number of electrons involved in a current of 1 A, we use the formula:I = n × ewhere I is the current (1 A), n is the number of…
Correct answer: 6.42 × 10^18- A. Resistance and resistivity
- B. Conductivity and resistivity
- C. Electromotive force and potential difference
- D. Resistivity and temperature coefficient of resistivity
Explanation: The correct answer is Option C: Electromotive force and potential difference. Both are measured in volts (V) and have the same dimensions.
Correct answer: Electromotive force and potential difference- A. Their bodies have high resistance
- B. Their feet are good insulators
- C. There is a negligible potential difference between their feet
- D. Wires are insulated
Explanation: Birds perched on an overhead transmission line are not harmed because both of their feet are at the same electrical potential, eliminating…
Correct answer: There is a negligible potential difference between their feet- A. Charge
- B. Energy
- C. Mass
- D. Momentum
Explanation: Kirchhoff's first law is a manifestation of law of conservation of charge, if there is no sink or source of charge at a point, the total…
Correct answer: Charge- A. Cross sectional of the sample
- B. The length of sample
- C. The mass of an electron
- D. The electric field in the sample
Explanation: Drift velocity is proportional to current. In a resistive material, it is also proportional to the magnitude of an external electric…
Correct answer: The electric field in the sample13836. The sum of the e.m.f and potential differences around a closed circuit is zero is a consequence of:
- A. Ohm's law
- B. Newton's 2nd law
- C. Conservation of energy
- D. Conservation of charge
Explanation: The second law of Kirchoff states that around any closed loop in a circuit, the sum of potential differences and emf is zero.
Correct answer: Conservation of energy- A. 7A out of the junction
- B. 7A into the junction
- C. 3A out of the junction
- D. 3A in to the junction
Explanation: D. Kirchoff's Junction rule states that the total current into a junction is equal to that out of the junction hence 3+4in = 5+2out
Correct answer: 3A in to the junction- A. 0.25 Ω in parallel
- B. 0.25 Ω in series
- C. 0.50 Ω in parallel
- D. 0.50 Ω in series
Explanation: A galvanometer is converted into an ammeter by connecting a low resistance in parallel with the galvanometer.
Correct answer: 0.25 Ω in parallel- A. 0.12V
- B. 2.0V
- C. 6.0V
- D. 24V
Explanation: The correct answer is 6.0V, determined by using the formula P = VI, where P is power, V is voltage, and I is current.
Correct answer: 6.0V- A. Mass
- B. Energy
- C. Momentum
- D. Charge
Explanation: Kirchhoff's current law (KCL) is based upon the law of conservation of charge.
Correct answer: Charge