Explanation

• Poisson’s Ratio (μ or ν) is the ratio of lateral strain to longitudinal strain.
• Formula: ν = Lateral Strain / Longitudinal Strain
• Longitudinal strain occurs in the direction of the applied load.
• Lateral strain occurs perpendicular to the applied load.
• It is a dimensionless quantity.
• It is represented by the Greek letter ν (nu).

Explanation

• According to Fleming's Right-Hand Rule, the forefinger points in the direction of the magnetic field (lines of force).
• The thumb shows the motion of the conductor.
• The forefinger shows the magnetic field (N → S).
• The middle finger shows the induced current (or induced e.m.f.).
• This rule is used for electric generators.

Last verified on 10-07-2026

Explanation

• Sound waves in solvents (like liquids) travel as longitudinal waves, where particles vibrate parallel to the direction of wave propagation.
• These are a type of mechanical wave, requiring a medium to travel.

Last verified on 19-03-2026

Explanation

• A diode is a semiconductor device that allows electric current to flow in only one direction.
• It conducts current in forward bias and blocks it in reverse bias.
• A diode is made by joining P-type and N-type semiconductors to form a P-N junction.
• It is widely used for rectification, converting AC into DC.

Last verified on 09-07-2026

Explanation

When pressure is in atm and volume is in liters, use R = 0.0821 L·atm·mol⁻¹·K⁻¹.

The value of R depends on the units, not on the temperature (300 K).

Last verified on 09-07-2026

Explanation

• A black hole has an extremely strong gravitational field.
• Its gravity is so powerful that even light cannot escape from it.
• Black holes are formed when very massive stars collapse after exhausting their fuel.
• The boundary beyond which nothing can escape is called the event horizon.
• The idea of black holes comes from Einstein's General Theory of Relativity (1915).

Last verified on 08-07-2026

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

• Silver reflects approximately 95% of visible light.
• It is one of the best natural reflectors of visible light.
• Because of its high reflectivity.
• Silver is widely used in mirrors and optical instruments.
• It produces bright and clear reflections.

Last verified on 07-06-2026

Explanation

• Interference occurs when two waves overlap or cross each other.
• The waves may produce a stronger wave (constructive interference) or a weaker wave (destructive interference).
• It is a fundamental property of all types of waves, such as light, sound, and water waves.

Last verified on 07-07-2026

Explanation