Explanation

• Mass is a measure of the amount of matter in an object, and it remains constant regardless of where you are in the universe.
• Your mass on Earth is the same as your mass on the Moon, because you are still made up of the same amount of matter.
• However, your weight (the force exerted on you by gravity) would be different on the Moon, because the Moon has a much weaker gravitational field than Earth.

Explanation

• A close circuit, also known as a closed circuit.
• It is an electrical circuit that is complete and allows electricity to flow from the power source, through the wire, and to the bulb, causing it to light up.

Explanation

• Sound travels through a physical medium, such as air, water, or solid objects.
• It is transmitted through the vibration of particles in the medium.

Explanation

The force exerted by the atmosphere on the surface of the water is equal to the pressure multiplied by the area of the surface:

Force = Pressure x Area

= 100 kPa x (2 m x 1 m)

= 100,000 Pa x 2 m^2

= 200,000 N

= 200 kN

Explanation

The Angstrom (Å) is commonly used to measure wavelengths of light, where

1 Å = 10⁻¹⁰ meters.

Light wavelengths typically range from 4000 Å to 7000 Å.

Explanation

Explanation

Force is not a base quantity; it is calculated using base quantities (mass and acceleration).

It is a derived quantity because its SI unit (Newton) comes from kg·m/s².

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