Explanation

• A light year is the distance that light travels in one year.
• It is used to measure vast distances in space.
• Light moves at approximately 299,792 km per second.
• One light year ≈ 9.46 trillion kilometers (5.88 trillion miles).

Last verified on 17-03-2026

Explanation

• Ohm's law, description of the relationship between current, voltage, and resistance.
• Georg Simon Ohm stated that the electric current through a conductor is directly proportional to the voltage across it, provided temperature remains constant. 
• This relationship is called Ohm’s Law.

Last verified on 22-05-2026

Explanation

• Noise intensity is measured in decibels (dB).
• It indicates the loudness of sound.
• It helps assess noise pollution in cities, industries, and traffic areas.
• Noise pollution affects hearing, stress levels, and sleep.
• Reducing exposure above 85 dB is important for health protection.

Last verified on 19-03-2026

Explanation

• Sand is primarily composed of silicon dioxide (SiO₂).
• It is a chemical compound made of silicon and oxygen atoms in a 1:2 ratio.
• SiO₂ is found in quartz, glass, and sand naturally.
• It is hard, chemically stable, and insoluble in water.

Last verified on 16-03-2026

Explanation

• Pressure can be defined as the force acting per unit area.
• The unit of pressure is N/m² (Newton per square meter).
• It is also called Pascal (Pa).
• In SI base units kg⋅m−1⋅s−2
• Derivations from other quantities: p = F / A
• Dimension unit: M L^−1 T^-2.

Additional information 

The SI unit of energy/work is the joule (J)

Last updated on 09-03-2026

Explanation

Electric power: Rate of energy transfer.

It is measured in watts (W), or one joule per second.

Energy/Work: Measured in joules (J).

Charge: Measured in coulombs (C).

Pressure: Measured in pascals (Pa).

Electric current: Measured in amperes (A).

Electric resistance: Measured in ohms (Ω).

Temperature: Measured in kelvin (K).

Torque: Measured in newton metres (N m).

Velocity: Measured in meters per second (m/s).

Acceleration: Measured in meters per second squared (m/s²).

Explanation

SI (International System of Units) fundamental units include meter (length), kilogram (mass), and second (time).

All other units like Newton, Joule, etc., are derived from these base units.

Explanation

The SI unit of electric charge is the coulomb, represented by the symbol C.

One coulomb is the amount of charge that passes through a conductor carrying one ampere of current for one second.

It's also equal to the charge of about 6.24 quintillion electrons or protons.

Explanation

• Weight is a force.
• The unit of measurement for force is the Newton (N).

Explanation

Poison dosage is measured in milligrams (mg) based on body weight.

Even a small variation in mg can determine whether a substance is safe or toxic.