Explanation

The variation of Electric field (E) with distance (r) is observed as 1/r² for a spherical shell.

This is consistent with Gauss's Law for a spherical shell.

Explanation

For a rigid body that rotates about a fixed axis, the angle swept out by a line passing through any point on the body and intersecting the axis of rotation perpendicularly is called angular displacement.

Explanation

Reliability is a measurement of consistency.

Reliability refers to the consistency of a measure

Validity refers to the accuracy of a measure

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Explanation

If the frequency of electricity is doubled, the efficiency of the load decreases.

This is because electrical devices and systems are designed to operate optimally at a specific frequency, and doubling it can disrupt their performance.

Explanation

The renewable energy sources are:

• Water energy
• Wind energy
• Tidal energy
• Hydroelectric
• Ocean energy
• Geothermal energy
• Biomass
• Biogas

The non-renewable energy sources are:

• Fossil fuels or Hydrocarbon fuel (Oil, Natural gas, Coal)
• Nuclear energy

Explanation

• The magnet is the part of a bicycle dynamo that spins to generate electricity.
• When the magnet rotates, it induces an electric current in the coils of the dynamo.
• It producing electricity to power the bike's lights or other accessories.

Explanation

• 10^-9 second = Nano second (ns)
• 10^-6 second = Micro second (μs)
• 10^-3 second = Milli second (ms)
• 10^-2 second = Centi second (cs)
• 10^-1 second = Deci second (ds)

Explanation

The minimum angle of resolution (θ) for a lens of diameter (D) and light of wavelength (λ) passing through it can be expressed as:

𝜃= 1.22 𝜆 / 𝐷​

Where:

𝜆 is the wavelength of light

𝐷 is the diameter of the lens

The resolution power (R) is defined as the reciprocal of the angle of resolution:

𝑅 = 1 / 𝜃

Substituting the expression for 𝜃 into the equation for resolution power (R):

𝑅 = 1 / 1.22  𝜆 / 𝐷

Simplifying this expression:

𝑅 = 𝐷 / 1.22 𝜆 

So, the formula for the relation between resolution power (R) and the diameter of the lens (D) is:

𝑅 = 𝐷 / 1.22 𝜆

Explanation

• A telescope is an instrument that gathers light from distant sources.
• Such as stars, planets, galaxies, and other celestial objects.
• It allowing us to study and observe them in greater detail.

Explanation

• Red stars, also known as red dwarfs, typically have a surface temperature around 3000°C (5400°F).
• This is the coolest temperature range for stars, and it's what gives them their distinctive red color.