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 658 of 697
- A. Increased
- B. Decreased
- C. Reduced to zero
- D. Remain Constant
Explanation: As the elevator pushes upward, the downward force, i.e., weight, will appear to increase. Weff = mgeff geff = (g + a)
Correct answer: Increased- A. Visible light.
- B. Invisible infra-red.
- C. Ultra-violet.
- D. Ordinary light.
Explanation: In a material the speed of a wave, light, becomes v=c/n, where n is the refractive index of the material, n differs for each wavelength…
Correct answer: Invisible infra-red.- A. 50 to 1000
- B. 50
- C. 30
- D. 5
Explanation: A single mode or monomode step index fibre allows the propagation of only one transverse electromagnetic mode and hence the core diameter…
Correct answer: 5- A. Telescope
- B. Convex mirror
- C. Convex lens
- D. Concave lens
Explanation: Convex lenses are used in eyeglasses as they increase refraction and accordingly reduce the focal length hence making the images look…
Correct answer: Convex lens- A. Image size to object size.
- B. Object size to image size.
- C. Eyepiece size to object size.
- D. None of these.
Explanation: The magnification produced by a lens is defined as the 'ratio of the height of the image or image distance, to the height of the object or…
Correct answer: Image size to object size.13146. Light year is a measure of:
- A. Distance
- B. Time
- C. Intensity of light
- D. Velocity
Explanation: A light-year is the distance a beam of light travels in a single Earth year, which equates to approximately 6 trillion miles or 9.7…
Correct answer: Distance- A. Wavelength of photons
- B. Wave number of photons
- C. Energy of photons
- D. Frequency of photons
Explanation: Explanation:The extent of bonding of a light ray after passing through prism depends upon wavelength of photons.
Correct answer: Wavelength of photons- A. c = 2 fd
- B. c = 2π f / d
- C. c = 16 f / d
- D. c = 16 fd
Explanation: Explanation:c = 16fd is the correct formula to calculate the speed of light in Michelson's Experiment.
Correct answer: c = 16 fd- A. λ/4
- B. λ/2
- C. λ
- D. λ/3
Explanation: The correct answer is λ/2. In the Newton ring apparatus, when light reflects off the lens and glass plate at the point of contact, a phase…
Correct answer: λ/213150. In the case of a grafting spectrometer, the resolving power 'R' of the grating is defined as:
- A. λ / Δλ
- B. λ / D
- C. λ / λ1
- D. N x m
Explanation: The resolving power 'R' of a grating is defined by the formula R = λ / Δλ, where 'λ' is the wavelength and 'Δλ' is the smallest difference…
Correct answer: λ / Δλ- A. Visible light
- B. Ultraviolet light
- C. Ordinary light
- D. Invisible infrared light
Explanation: Infrared light travels fastest in optical fibers due to its longer wavelength, which minimizes scattering and absorption.
Correct answer: Invisible infrared light- A. Diffraction of Light
- B. Polarization of Light
- C. Quantization of Light
- D. Interference of Light
Explanation: The phenomenon of bending of light around the corners of obstacles in the path of light and spreading into the regions of geometrical…
Correct answer: Diffraction of Light13153. The value of the least distance of distinct vision or near point is _ for a normal human eye.
- A. 20 cm
- B. 25 cm
- C. 10 cm
- D. 15 cm
Explanation: The near point of the eye is the minimum distance of the object from the eye, which can be seen distinctly without strain.
Correct answer: 25 cm- A. 25 cm
- B. 22 cm
- C. 35 cm
- D. 20 cm
Explanation: This is approximately 25 cm from the eye. The normal human eye can focus a sharp image of an object on the eye if it is located anywhere…
Correct answer: 25 cm- A. 5
- B. 7
- C. 6
- D. 8
Explanation: Using M= 1 + d/f Putting values given in the question M= 1+25/5 M= 1+5=6
Correct answer: 6- A. Expanding
- B. Contracting
- C. Stationary
- D. Oscillating
Explanation: The Doppler red-shift of light observed from distant stars and galaxies gives evidence that the universe is expanding (moving away from a…
Correct answer: Expanding- A. 6 x 10^-7 m
- B. 4 x 10^-6 m
- C. 5 x 10^-7 m
- D. 3 x 10^-6 m
Explanation: We know, for diffraction grating: dsin𝜭=m𝞴 Where d is the reciprocal of lines per centimeter.
Correct answer: 5 x 10^-7 m- A. 42.5 Hz
- B. 85 Hz
- C. 220 Hz
- D. None of these
Explanation: The speed of the sound is = 340m/sIn an open pipe , the length of the pipe contains half a wavelength which means L= λ/2.Using the…
Correct answer: 85 Hz13159. An organ pipe closed at one end has a length of 25 cm. Wavelength of the fundamental note is:
- A. 25 cm
- B. 50 cm
- C. 100 cm
- D. 75 cm
Explanation: The fundamental wavelength for an organ pipe closed at one end is given by the formula λ = 4L/n, where L is the length of the pipe and n…
Correct answer: 100 cm- A. π/2
- B. π
- C. 3π/2
- D. 2π/3
Explanation: Given the AC voltage is in the form of a sinusoidal wave starting from 0, the positive peak is at π/2 and thus the negative peak is at…
Correct answer: 3π/2