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

• The SI unit of electric current is Ampere (A).
• Electric current measures the flow of electric charge.
• Defined using the elementary charge (e = 1.602176634 × 10⁻¹⁹ C).
• Named after: André-Marie Ampère (scientist).
• 1 Ampere = 1 Coulomb per second (1 A = 1 C/s).

Last verified on 08-06-2026

Explanation

• A Barometer is an instrument used to measure air (atmospheric) pressure.
• It helps in weather forecasting by measuring changes in atmospheric pressure.
• The mercury barometer is the oldest type of barometer.
• It was invented by Evangelista Torricelli in 1643.
• Barometers are widely used in meteorology and aviation.

Last verified on 09-07-2026

Explanation

• Sputnik-1 was launched by the USSR (Soviet Union) on 4 October 1957.
• It was the world's first artificial satellite, beginning of the Space Age.
• It started the Space Race between the Soviet Union and the United States.
• Launch Site: Baikonur Cosmodrome, Kazakhstan
• Weight: 83.6 kg
• Orbital Period: About 96 minutes

Last verified on 09-03-2026

Explanation

• Convex lenses are known as Converging lenses.
• Because they bring parallel light rays to a single focal point.
• A convex lens is thicker at the center and thinner at the edges.
• It forms real and inverted images when the object is beyond the focal length.
• It can also produce a virtual, erect, and magnified image when the object is placed within the focal length.

Additional information:

• Concave lens is also called a diverging lens.

Last verified on 11-03-2026