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 675 of 697
- A. 4.8%
- B. 3.2%
- C. 1.6%
- D. 0.8%
Explanation: The uncertainty in a measurement involving exponentiation is multiplied by the exponent.
Correct answer: 3.2%- A. 7
- B. 8
- C. 5
- D. 3
Explanation: The number of significant figures in a measurement includes all the certain digits plus the first uncertain digit.
Correct answer: 7- A. 3 s.f
- B. 2 s.f
- C. 5 s.f
- D. 8 s.f
Explanation: When determining the number of significant figures in a measurement, focus on the digits that are known with certainty and the first…
Correct answer: 3 s.f- A. Five
- B. One
- C. Two
- D. Three
Explanation: All non zero digits are significant figures and in this case there are 3 significant or non zero digits hence option D is the right choice.
Correct answer: Three13485. Which experimental teachnique reduces the systematic error of the quantity being investigated?
- A. Adjusting an ammeter to remove its zero error before measuring a current
- B. Measuring several internodal distances on a standing wave to find the mean internodal distance
- C. Measuring the diameter of a wire repeatedly and calculating the average
- D. Timing a large number of oscillations to find a period
Explanation: Systematic error means that measurements of the same thing will vary in predictable ways.
Correct answer: Adjusting an ammeter to remove its zero error before measuring a current- A. 17%
- B. 30%
- C. 15%
- D. 90%
Explanation: Kinetic Energy = mv^2/2Percentage Error in KE = Percentage Error in Mass + 2(Percentage Error in Speed) The question states percentage…
Correct answer: 17%- A. 0
- B. 1
- C. 2
- D. 3
Explanation: The number 500 is a whole number and has three significant figures: the digit '5' and the two trailing zeros.
Correct answer: 3- A. 2%
- B. 4%
- C. 6%
- D. 8%
Explanation: First we find out the % uncertainty in current (0.05)/2.5 x 100 = 2%. Then we note the formula of power dissipated is 12 x R so the =…
Correct answer: 6%- A. 65V
- B. 260V
- C. 60V
- D. 10V
Explanation: We know that generated EMF in the DC generator is given by the formula: E = ΦPNZ/60A Where Φ= flux P= No. of poles N= speed Z= No.
Correct answer: 65V- A. Magnetic field
- B. Electric field
- C. Induced emf
- D. Altemating current
Explanation: Protip: Static/ not moving charge: electric field Charge moving with constant velocity: electric and magnetic field
Correct answer: Magnetic field- A. Be maximum
- B. Be zero
- C. Depend on the size of the coil
- D. None of above
Explanation: Since the coil is moving parallel to a uniform magnetic field, the magnetic flux associated with the coil will remain zero during the…
Correct answer: Be zero- A. Area of the coil:
- B. Shape of the coil
- C. Turns of coil:
- D. Strength of magnetic field in which coil rotates
Explanation: According to Faraday's law of electromagnetic induction, the magnitude of the induced electromotive force (emf) and hence the current…
Correct answer: Strength of magnetic field in which coil rotates- A. Current
- B. Resistance
- C. Magnetic induction
- D. Potential difference
Explanation: The time rate of change of magnetic flux has the same dimensions as potential difference, which is measured in volts (V).
Correct answer: Potential difference- A. 0 mA
- B. 2 mA
- C. 2.8 mA
- D. 20 mA
Explanation: The induced current in the loop is 2.8 mA. The rate of loss of kinetic energy is equal to the power dissipated in the loop, which is given…
Correct answer: 2.8 mA- A. Isothermal
- B. Isochronic
- C. Adiabatic
- D. Isobaric
Explanation: Isochronic or isochoric processes are carried out at constant volume.
Correct answer: Isochronic- A. Δθ = Δu + Δw
- B. Δθ = Δu
- C. Δθ = Δw
- D. None
Explanation: First law of thermodynamics states " energy can neither be created nor destroyed, it can only be altered/changed into different forms".
Correct answer: Δθ = Δu + Δw- A. Isobaric process
- B. Isothermal process
- C. Adiabatic process
- D. Isochor process
Explanation: Adiabatic is a process in which heat neither enters nor leaves a system, but the temperature of the system still changes.
Correct answer: Adiabatic process- A. The efficiency of the working substance
- B. The ideal gas scale temperature
- C. The thermal conductivity at the working substance
- D. None of the above
Explanation: The ratio of heat accepted to the heat rejected by a Carnot engine gives the efficiency of the working substance.
Correct answer: The efficiency of the working substance- A. Positive
- B. Negative
- C. Zero
- D. Constant
Explanation: Work is defined as the force applied over a distance, resulting in the displacement of an object.
Correct answer: Zero- A. Total internal energy has decreased
- B. The system has lost heat
- C. Work done by the system
- D. Work done on the system
Explanation: In the first law of thermodynamics, the expression for the change in internal energy of a system can be given as:∆U = Q - WIf the…
Correct answer: Work done by the system