Explanation

• MRI stands for Magnetic Resonance Imaging.
• It is a medical imaging technique.
• It uses strong magnetic fields and radio waves to create detailed images of organs and tissues.

Last verified on 03-09-2026

Explanation

• Marconi invented Radio.
• Radio was invented in 1895.
• Guglielmo Marconi was an Italian inventor.

Last verified on 12-08-2026

Explanation

• Inventor: Thomas Alva Edison.
• Country: United States.
• Practical incandescent bulb: 1879.
• Other contributions: Electric power, sound recording, motion pictures.
• Famous invention: Phonograph.

Last verified on 03-09-2026

Explanation

• The Doppler Effect is the change in the observed frequency of sound due to the relative motion between the source and the observer.
• If the source and observer move toward each other, the observed frequency increases.
• If they move away from each other, the observed frequency decreases.
• A common example is the changing pitch of an ambulance siren as it passes by.

Last verified on 02-09-2026

Explanation

• Ibn al-Haytham presented the theory of reflection and refraction of light.
• He is also known as Alhazen.
• His work, particularly his "Book of Optics", is titled Kitab al-Manazir, written during 1011–1021.
• Born: c. 965 (c. 354 AH) Basra, Buyid Emirate
• Died: c. 1040 (c. 430 AH)[1] (aged around 75) Cairo, Fatimid Caliphate

Last verified on 02-09-2026

Explanation

• Pressure is a scalar quantity.
• 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 a pascal (Pa).
• In SI base units: kg⋅m−1⋅s−2
• Derivation from other quantities: p = F / A
• Dimensional unit: M L^−1 T^-2.

Explanation

The particle's path is a helix.

Reasoning:

• Velocity has two components:
  • Parallel to the fields → electric force accelerates it along the axis
  • Perpendicular to the fields → magnetic force makes it circle around the axis
• Combined → helical path (with changing pitch as it speeds up/slows down)

Explanation

• Length, mass, and time are fundamental physical quantities.
• They can be measured using standard units.
• SI units are the metre for length, the kilogram for mass, and the second for time.

Explanation

Formula:  

Mean = Sum of observations / Number of observations  

Given:  

Mean = 50  

Number of observations = 10  

Sum of observations = Mean _ Number of observations  

= 50 _ 10  

= 500

Last verified on 11-07-2026

Explanation

• Humidity is the measure of the amount of moisture (water vapour) in the air.
• A hygrometer is used to measure relative humidity.
• A psychrometer is an example of a hygrometer.
• Relative humidity tells us the ratio of water vapour present in the air compared with the maximum amount the air can hold at a given temperature.
• Humidity is commonly expressed as a percentage (%).

Last verified on 23-08-2026