Physics MCQs

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Lambert’s Law states that the intensity of emitted light from a surface is directly proportional to the cosine of the angle between the line of view and the normal to the surface. A Lambertian surface is a surface that follows this rule exactly. In practice, most surfaces are not perfectly Lambertian. A surface which obeys Lambert’s law is said to be Lambertian, and exhibits Lambertian reflectance. Such a surface has the same radiance when viewed from any angle.

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The human eye is sensible to light having wavelength roughly between 400 nm and 700 nm. When illumination is enough (in daylight) the maximum sensitivity is in the green region at 555 nm. However, human eyes are the most sensitive to yellow colour light.

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Red light has a longer wavelength than violet light and the other colours of visible light have intermediate wavelengths. As light passes from air into glass, there is reduction of velocity. Due to longer wavelengths, red waves travel fastest and is refracted the least, while violet waves travel the slowest and is refracted the most because of their smaller wave length.

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Interference usually refers to the interaction of waves that are correlated or coherent with each other, either because they come from the same source or because they have the same or nearly the same frequency. Interference effects can be observed with all types of waves, for examplesound waves, surface waves, and electromagnetic waves (e. g. , light waves, etc). Similarly, Diffraction occurs with all waves, including sound waves, water waves, and electromagnetic waves such as visible light, X-rays and radio waves.

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A concave mirror is a mirror that is curved inward in the middle. It is also known as a converging mirror as this reflecting surface collects light incident on its surface, and reflects the parallel rays of light towards a common focus.

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The total resistance of a number of resistors in series is equal to the sum of all the individual resistances. In other words, if we have two resistors R1 and R 2 in series, the total resistance of the network R = R1+R2. So, in this case, the net resistance increases. In contrast, the net resistance decreases when the resistors are connected in parallel.

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A tuning capacitor or tuning condenser is a variable capacitor used in an electronic circuit of a radio. It usually confects in parallel to a loop antenna and its capacitance may be intentionally and repeatedly changed mechanically or electronically.

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A semiconductor is a substance with electrical conductivity intermediate between that of an insulator and a conductor. Elemental semiconductors include antimony, arsenic, boron, carbon, germanium, selenium, silicon, sulfur, and tellurium. Silicon is the best-known of these, forming the basis of most integrated circuits (ICs).

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In jet engines, a large volume of gases produced by the combustion of fuel is allowed to escape through a jet in the backward direction. Due to the very high speed or velocity, the backward rushing gases have a large momentum. They impart and equal and opposite momentum to the jet engine due to which the jet engine moves forward with a great speed. Thus, we can say that the jet engines work on the principle of conservation of linear momentum.

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Max Planck was awarded the 1918 Nobel Prize in Physics for his work on quantum theory. Planck was a German theoretical physicist who originated quantum theory, one of the fundamental theories of modern physics. His work on quantum theory revolutionized mankind’s understanding of atomic and subatomic processes.
Planck’s work on quantum theory laid the foundation for quantum theory. In 1900, Planck discovered the quantum of action, now known as Planck’s constant, h. This work earned him the Nobel Prize in Physics in 1918. Planck received his Nobel Prize one year later, in 1919.