Explanation

• The retina is composed of light-sensitive neurons (photoreceptors).
• It detects light and converts it into nerve signals sent to the brain.
• It contains two main cells: rods and cones.
• These cells help in vision, color detection, and low-light vision.

Last verified on 25-06-2026

Explanation

• Mass and Length are base quantities in SI units.
• Length SI Unit: meter (m)
• Mass SI Unit: kilogram (kg)

Additional information:

Base Quantities in SI System:

• Time (second)
• Electric current (ampere)
• Temperature (kelvin)

Last verified on 16-06-2026

Explanation

• Electric fire alarms work on the principle of expansion of metals due to heat.
• A fire alarm uses a bimetallic strip that bends when heated because different metals expand at different rates.
• This bending completes an electric circuit and activates the alarm.
• It is an example of the thermal expansion principle.

Last verified on 25-06-2026

Explanation

• Pneumatics is the study of the mechanical behavior and application of gases, especially compressed air, under pressure.
• It deals with the use of pressurized gases to produce mechanical motion.
• Pneumatic systems are commonly used in machines, tools, and industrial equipment.
• The word comes from the Greek word "pneuma" meaning air or breath.

Last verified on 25-06-2026

Explanation

• Opposite electrostatic charges attract each other.
• Positive (+) and negative (−) charges pull toward each other due to electrostatic force.
• Like charges (positive-positive or negative-negative) repel each other.
• This principle is explained by Coulomb’s Law.

Last verified on 25-06-2026

Explanation

• Lamp is not a form of energy.
• It is a device that produces light.
• Heat, sound, and light are all different forms of energy.
• Energy is the ability to do work or produce change.
• A lamp converts electrical energy into light energy.

Last verified on 16-06-2026

Explanation

• The primary colors of white light are Red, Green, and Blue (RGB).
• White light is produced when these three colors of light combine in equal amounts.
• This is called the additive color model.
• RGB is used in screens, televisions, and digital displays.

Additional information:

The primary colors of Pigment is:

• Red
• Yellow
• Blue

Last verified on 25-06-2026

Explanation

• Neil Armstrong was the first human to set foot on the Moon on July 20, 1969, during NASA's Apollo 11 mission.
• His famous words upon landing were, "That's one small step for man, one giant leap for mankind."

Additional information:

• Neil Alden Armstrong was died on August 25, 2012.
• He was born on August 5, 1930.

Last verified on 01-04-2026

Explanation

• The Big Bang Theory was proposed by Georges Lemaître in 1927.
• He suggested that the universe began from a highly dense state.
• His idea was called the “Primeval Atom” theory.
• The theory explains the origin and expansion of the universe.

Last verified on 25-06-2026

Explanation

• Saturn is the second-largest planet in the solar system.
• Ganymede (Moon of Jupiter) is the largest satellite in the solar system.

Planets and Natural Satellites:

1. Mercury: 0
2. Venus: 0
3. Earth: 1 (Moon)
4. Mars: 2 (Deimos, Phobos)
5. Jupiter: 95
6. Saturn: 274
7. Uranus: 27

Last verified on 02-05-2026