Explanation

The least distance of distinct vision for a normal human eye is 25 cm.

It is the minimum distance at which the eye can see an object clearly without strain.

Explanation

The aperture refers to the diameter of the lens through which light enters.

It controls the amount of light reaching the lens, affecting brightness and focus.

Explanation

A mass attached to a spring oscillates back and forth around an equilibrium position, following Hooke's Law.

This periodic motion with a restoring force proportional to displacement defines simple harmonic motion (SHM).

Explanation

When θ = 0°, the force and displacement are in the same direction, and the work done is maximum.

The formula simplifies to W = F ⋅ d, meaning all the force contributes to the displacement.

Explanation

In the photoelectric effect, photons strike a metal and release electrons.

In x-ray production, high-energy electrons strike a metal and emit photons — the reverse of the photoelectric effect.

Explanation

An ammeter is always connected in series with a circuit to measure the current. 

In a series circuit, the current flows through each component one after the other, meaning the same current passes through every device in the circuit.

Since an ammeter is designed to measure the current flowing through a circuit, placing it in series ensures that the entire current passes through it. 

Explanation

 The unimportant factor in describing a satellite's orbit is the mass of the satellite. 

Explanation

When two identical waves move in opposite directions, they give rise to stationary waves. 

Beats:

Beats occur when two waves with slightly different frequencies interfere, producing a fluctuating amplitude that can be heard as a pulsating sound. 

Constructive interference:

This happens when two waves with the same phase overlap, leading to an increased amplitude. 

Destructive interference:

This happens when two waves with opposite phases overlap, leading to a decreased or zero amplitude. 

Explanation

The quantity that indicates the state and direction of a vibrating body is phase. 

Explanation

Fringe spacing in a double-slit experiment increases when using light with a longer wavelength.

Therefore, red light will produce the largest fringe spacing compared to blue, green, or yellow light.