Explanation

Two light waves that are not coherent cannot produce interference.

Interference requires that the light waves maintain a constant phase relationship, which is a characteristic of coherent sources.

Non-coherent sources have fluctuating phase differences, leading to the wash-out of interference patterns.

Explanation

This formula comes from the Rayleigh criterion for the minimum resolvable angle (θₘᵢₙ) in optical systems like lenses or telescopes:

$$theta_{min} = frac{1.22 , lambda}{D}$$

Where:

• $lambda$ = wavelength of light

• $D$= diameter of the lens aperture

This equation gives the angular resolution or resolving power of the lens.

Explanation

The energy required to excite an electron from the second orbit to the third orbit is:

ΔE = 13.6Z^2(1/4 - 1/9) eV

Given ΔE = 42.7 eV:

42.7 = 13.6Z^2(1/4 - 1/9)

Solving for Z:

Z = 4

Explanation

A free-falling object near Earth's surface accelerates at approximately 9.80 m/s² due to gravity.

This is known as the acceleration due to gravity (g).

Explanation

Liquids that conduct an electric current are called electrolytes.

They contain ions that move freely.

It allowing the electrical current to pass through.

Explanation

• As gas particles move faster, they exert a greater force on the container walls, resulting in increased pressure.
• This relationship is described by the kinetic molecular theory, which states that the pressure of a gas is directly proportional to the square of its velocity.

Explanation

• Dust and gas in the interstellar medium (ISM) can absorb and scatter starlight.
• It leading to a reduction in the brightness of stars as seen from Earth.
• This is known as interstellar extinction.

Explanation

• The movement of free electrons is defined as electric current, which is the flow of electrons through a conductor, such as a wire.
• Electric charge refers to the property of matter, electric field is the force that surrounds charged particles, and electric potential is the potential energy per unit charge.

Explanation

• The speed of sound in diamond is approximately 12,000 meters per second (m/s).
• It is one of the fastest speeds of sound among all materials.

The speeds of sound in different materials:

• Air: 343 m/s
• Water: 1433 m/s
• Wood: 3300-3600 m/s
• Brick: 4176 m/s
• Steel: 6100 m/s
• Diamond: 12000 m/s

Explanation

A satellite is an object that orbits a larger celestial body, such as a planet or star.

Examples:

• Moons (natural satellites) that orbit planets
• Artificial satellites (like the International Space Station) that orbit Earth