Physics General Knowledge Questions: Physics GK Question for Competitive Exams
______ in a particular direction is velocity.
(A) Acceleration
(B) Displacement
(C) Speed
(D) Distance
Correct Answer : C
Explanation :
A straight object moving in a specific direction is said to have velocity. As a result, velocity refers to an object's speed in a specific direction.
What happens to the temperature of a liquid when it evaporates?
(A) increase
(B) remain unchanged
(C) grow faster
(D) decrease
Correct Answer : D
Explanation :
During the process of evaporation of liquid the temperature of the liquid decreases because the surface molecules while evaporating take some amount of energy from the other molecules of liquid. Thus, evaporation leads to cooling. Kinetic energy is proportional to absolute temperature.
The reason for the diffusion of light in the atmosphere is?
(A) Carbon dioxide
(B) Water Vapor
(C) Helium
(D) Dust Particles
Correct Answer : D
Explanation :
The correct answer is dust particles. Diffusion of light in the atmosphere takes place due to dust particles. Diffusion is the net fluctuation of anything (for example, atoms, ions, molecules, energy) from a region of higher concentration to a region of lower concentration.
In optics, the refractive index of a substance is described by the formula n = c/v, where c is:
(A) the speed of light in medium
(B) the centre of curvature
(C) the radius of the sphere
(D) the speed of light in vacuum
Correct Answer : D
Explanation :
Refractive Index Formulan is the refractive index. c is the velocity of light in a vacuum ( 3 × 108 m/s) v is the velocity of light in a substance.
Who discovered X-rays?
(A) Faraday
(B) Newton
(C) Rutherford
(D) none of these
Correct Answer : A
The working principle of the washing machine is?
(A) Sub-Centre
(B) Diffusion
(C) Centrifugation
(D) Dialysis
Correct Answer : C
Explanation :
The working principle of a washing machine is centrifugation. Centrifugation is a separation process that uses the action of centrifugal force to promote accelerated settling of particles in a solid-liquid mixture.
What is the reason for the spherical shape of a liquid drop?
(A) Viscosity
(B) Light Load
(C) Surface Tension
(D) Atmospheric Pressure
Correct Answer : C
Explanation :
Due to surface tension, surface tries to minimize its area. As sphere has the minimum surface area among all geometrical shapes thus, liquid drop becomes spherical.
The colour of the sky appears to be blue.
(A) due to diffraction
(B) due to scattering
(C) due to reflection
(D) due to refraction
Correct Answer : B
Explanation :
The sky appears blue to the human eye as the short waves of blue light are scattered more than the other colours in the spectrum, making the blue light more visible.
The application of low-temperature engines is?
(A) submarine propulsion
(B) research on superconductivity
(C) rocket technology
(D) frost free refrigerators
Correct Answer : C
Explanation :
Low-temperature combustion (LTC) is a recent engine technology that can reduce the oxides of nitrogen (NOx) and soot emissions simultaneously while maintaining higher thermal efficiency.
he temperature at which ice, water and vapour remain in equilibrium is called?
(A) freezing point
(B) triple point
(C) critical temperature
(D) boiling point
Correct Answer : B
Explanation :
The technical term for this is the triple point of water since at this temperature, not only solid ice and liquid water, but also water vapor coexist. The temperature and pressure conditions that allow a substance's gaseous, liquid, and solid phases to exist in equilibrium is called triple point of the substance.
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Rajesh Bhatia
A Writer, Teacher and GK Expert. I am an M.A. & M.Ed. in English Literature and Political Science. I am highly keen and passionate about reading Indian History. Also, I like to mentor students about how to prepare for a competitive examination. Share your concerns with me by comment box. Also, you can ask anything at linkedin.com/in/rajesh-bhatia-7395a015b/.
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