Explanation

The postulate that "Collisions of gas molecules are elastic" is not a part of the Kinetic Molecular Theory of Gases.

Explanation

Among the given options, the closest one is 45000 Å.

Explanation

A vector field with a vanishing curl is called "irrotational."

Explanation

FCC (Face-Centered Cubic) lattice is the reciprocal lattice of the BCC (Body-Centered Cubic) lattice.

Explanation

Einstein’s photoelectric equation is "hv = hvo + (1/2 mv^2) max", where:

• hv is the energy of the incident photon
• h is Planck's constant
• vo is the threshold frequency
• m is the mass of the emitted photoelectron
• max is the maximum kinetic energy of the emitted photoelectron.

Explanation

Increasing the number of slits on a diffraction grating will increase the intensity of the central maximum of the diffraction pattern.

Explanation

Explanation

• A four-level laser is a type of laser that has four energy levels involved in the lasing process.
• The He-Ne laser (Helium-Neon laser) is a common example of a four-level laser.
• It works by exciting helium atoms, which then transfer their energy to neon atoms, causing them to emit laser light.

Explanation

When the stress applied to the body is increased beyond the maximum value and then removed after some time, the body will "not be able to return to its original position." This situation is known as plastic deformation, where the body undergoes permanent deformation.

Explanation

The parameters that Kepler’s Law of period relates to are "the semi-major axis and the time period."