Physics General Knowledge Questions: Physics GK Question for Competitive Exams

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.

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.

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.

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.

Correct Answer : A

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.

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.

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.

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.

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.