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 693 of 697
- A. 560
- B. 300
- C. 200
- D. 800
Explanation: To calculate the rate of energy dissipation (power) in an X-ray tube, we use the formula P = IV, where P is the power in watts, I is the…
Correct answer: 300- A. Half wavelength
- B. Integral number of wavelength
- C. Quarter wavelength
- D. Odd integral number of half wavelength
Explanation: For two coherent monochromatic sets of waves to interfere constructively in the region of superposition, the path difference between them…
Correct answer: Integral number of wavelength- A. Fringe width will decrease
- B. Fringe width will increase
- C. Fringe width will remain the same
- D. Fringe width will become less intense
Explanation: Fringe width will increase: If the orange light has a longer wavelength compared to the green light, then the fringe width will increase.
Correct answer: Fringe width will increase- A. Interference
- B. Dispersion of light
- C. Scattering of light
- D. Refraction of light
Explanation: The colors in a soap bubble are due to interference of light. When light reflects off the outer and inner surfaces of the thin soap film…
Correct answer: Interference- A. The lamps are not point sources.
- B. The lamps emit light of different amplitudes.
- C. The light from the lamps is not coherent.
- D. The light from the lamps is white.
Explanation: When light from two separate lamps falls on a screen, interference patterns typically do not form because the light from each lamp is not…
Correct answer: The light from the lamps is not coherent.- A. Refraction and diffraction
- B. Interference and reflection
- C. Interference and diffraction
- D. Diffraction and polarization
Explanation: When monochromatic light passing through two parallel slit and falls on a screen, the pattern produced is due to interference and…
Correct answer: Interference and diffraction- A. 2x
- B. x
- C. 3x
- D. 4x
Explanation: For double slits: Wavelength λ = xa / Dwhere x: separation of fringes,a: slit separation / distance between slits,D = distance from slits…
Correct answer: x- A. Dispersion
- B. Absorption of light
- C. Scattering of light
- D. Interference of light
Explanation: The correct answer is interference of light. The colors seen in thin films result from the interference of light waves reflected from the…
Correct answer: Interference of light- A. 0.5 Sec
- B. 2 Sec
- C. 1 Sec
- D. 0.25 Sec
Explanation: The beat frequency is determined by the difference between the two frequencies: Δf = 260 Hz - 256 Hz = 4 Hz.
Correct answer: 0.25 Sec- A. Halved
- B. Unchanged
- C. Doubled
- D. Zero
Explanation: In Young's double-slit experiment, the fringe width is calculated using the formula:wavelength * distance_to_screen /…
Correct answer: Unchanged- A. mπ
- B. 2 mπ
- C. mπ/2
- D. None
Explanation: Factual. General form for path difference is given as =2𝞹 Option A, C and D are not correct according to this.
Correct answer: 2 mπ- A. Positive
- B. Negative
- C. Imaginary
- D. Zero
Explanation: The temperature coefficient of resistance for a semiconductor is negative, indicating that its resistance decreases as temperature…
Correct answer: Negative- A. The air resistence just balances the force of gravity
- B. The force of gravity ois constant for all drops
- C. All drops fall from the same height
- D. The drops are small so force of gravity is negligible for them
Explanation: Terminal velocity, the steady speed achieved by an object freely falling through a gas or liquidLet's go into the imagination A raindrop…
Correct answer: The air resistence just balances the force of gravity13854. The maximum drag force on a sphere falling with zero acceleration is 9.8 N its real weight is:
- A. Zero
- B. 9.8 N
- C. 4.9N
- D. 19.6N
Explanation: The drag force experienced by an object falling with zero acceleration is equal to the weight of the object.
Correct answer: 9.8 N- A. 8 cms-1
- B. 16 cms-1
- C. 24 cms-1
- D. 32 cms-1
Explanation: Explanation is given below.Let the radius of bigger drop is R and smaller drop is r then4/3πR^3 = 8×4/3×πr^3or R=2r ....(i)Terminal…
Correct answer: 32 cms-1- A. Before hail
- B. After hail
- C. At the same time
- D. None of the above
Explanation: The correct answer is option B: 'After hail'. The rain drop, being less dense than the hail, experiences less gravitational force acting…
Correct answer: After hail- A. The heat capacity of working substances
- B. Only the temperature of two reservoirs
- C. The reservoir temperature and the heat capacity of working substance
- D. The reservoir temperature and the volume chnage during heat absorption
Explanation: The Carnot engine is a theoretical thermodynamic cycle proposed by Nicolas Léonard Sadi Carnot in 1824.
Correct answer: Only the temperature of two reservoirs- A. The density increases
- B. The latent heat increases
- C. The molecule vibrates more rapidly
- D. The melting point increases
Explanation: The changes that take place when a solid is heated (increase in temperature) are as follows:On increasing the temperature of solids, the…
Correct answer: The molecule vibrates more rapidly- A. Zero
- B. Positive
- C. Negative
- D. None of the above
Explanation: The Carnot Cycle is a thermodynamic cycle that consists of four subsequent reversible processes: isothermal expansion, adiabatic…
Correct answer: Zero- A. Enthalpy is constant
- B. Temperature is constant
- C. Pressure is constant
- D. No heat enters or leaves the system
Explanation: An isothermal change refers to a process in which the temperature of a system remains constant throughout the process.
Correct answer: Temperature is constant