Explanation

• Total standard zones: 24
• Earth rotation time: 24 hours
• Longitude per zone: 15 degrees
• Starting point: Greenwich (0°)
• It is used worldwide for time coordination.

Last verified on 14-06-2026

Explanation

• Light Year is the distance that light can travel in one year.
• The distance light travels in one year is known as light year.
• 1 light year is equal to 9.5 x 10¹²km.

Last verified on 30-03-2026

Explanation

• When a body moves upward, its height from the ground increases.
• Gravitational potential energy depends on height (P.E = mgh), so it increases as height increases.
• The increase in potential energy comes from the conversion of kinetic energy into potential energy.

Last verified on 18-06-2026

Explanation

• Picosecond (ps) = 10⁻¹² seconds
• SI prefix “pico” means 10⁻¹².
• 1 picosecond = one trillionth of a second.

Additional information:

• Microsecond (μs) = 10⁻⁶ seconds
• Nanosecond (ns) = 10⁻⁹ seconds
• Millisecond (ms) = 10⁻³ seconds
• Femtosecond (fs) = 10⁻¹⁵ seconds
• Attosecond (as) = 10⁻¹⁸ seconds
• Zeptosecond (zs) = 10⁻²¹ seconds
• Yoctosecond (ys) = 10⁻²⁴ seconds

Last verified on 17-06-2026

Explanation

• The dimension of viscosity is [ML⁻¹T⁻¹].
• Viscosity measures a fluid’s resistance to flow.
• Higher viscosity means thicker fluid (like honey).
• Lower viscosity means thinner fluid (like water).

Last verified on 17-06-2026

Explanation

• The unit of pressure is N/m² (Newton per square meter).
• It is also called Pascal (Pa).
• Pressure means force applied per unit area.
• Higher force or smaller area increases pressure.

Last verified on 17-06-2026

Explanation

• Honey has the maximum viscosity.
• Viscosity means resistance to flow.
• Honey flows very slowly due to high internal friction.

Last verified on 17-06-2026

Explanation

Kinetic energy formula = 1/2 × mass × velocity²  

Mass is constant.

If KE doubles, then velocity² must double.  

If velocity² becomes 2 times, velocity becomes √2 times.

So kinetic energy doubles by doubling √2 × velocity.

Last verified on 17-06-2026

Explanation

• Lenz’s law is based on the law of conservation of energy.
• It states that induced current always opposes the change causing it.
• This opposition prevents creation of energy from nothing.
• It ensures energy is neither created nor destroyed.

Last verified on 17-06-2026

Explanation

• At the center of the Earth, g = 0.
• Gravity from all directions cancels out at the center.
• So net gravitational force becomes zero.
• An object would feel weightless there.
• This is due to symmetrical distribution of Earth's mass.
• Earth’s surface gravity: 9.8 m/s²

Last verified on 17-06-2026