Explanation

• The weight of a body on Earth is the gravitational force acting on it.
• Since the body already weighs 51 N on the surface of Earth, its weight on Earth remains 51 N.
• Formula: Weight = Mass × Gravity (W = mg).

Last verified on 24-06-2026

Explanation

• HLA stands for Human Leukocyte Antigen.
• It is a system of proteins found on the surface of cells.
• It plays an important role in the immune system and body’s defense mechanism.
• HLA helps the body distinguish between self and foreign substances.

Last verified on 23-06-2026

Explanation

• 1 hp = 746 W
• 1 hp = 0.746 kW
• 1 kW = 1.34 hp
• 1 W = 0.00134 hp
• Standard unit system: SI unit of power is Watt

Last verified on 23-06-2026

Explanation

• The efficiency of a diesel engine is about 30–40%.
• It means only this percentage of fuel energy is converted into useful work.
• The remaining energy is lost as heat, friction, and exhaust gases.
• Diesel engines are generally more efficient than petrol engines.

Last verified on 23-06-2026

Explanation

• Name: Waldemar Haffkine
• Year: 1892
• Vaccine: Cholera vaccine (first effective form)
• Place of work: India (British India)
• Field: Microbiology / Immunology

Last verified on 23-06-2026

Explanation

• The main purpose of pre-natal ultrasound is to monitor the growth and health of the fetus during pregnancy.
• It helps doctors check the baby’s position, heartbeat, and development.
• It can detect abnormalities or complications early.

Last verified on 23-06-2026

Explanation

• Solar plates consist of photovoltaic (PV) cells.
• PV cells convert sunlight directly into electrical energy.
• These cells work on the photovoltaic effect. 
• They are usually made of semiconductor materials like silicon.

Additional information:

• Discovered photovoltaic effect: 1839 by Edmond Becquerel

Common types of solar cells:

1. Monocrystalline silicon cells
2. Polycrystalline silicon cells
3. Thin-film solar cells

Last verified on 23-06-2026

Explanation

• On average, the human body contains about 60–70% water.
• Adult males: 60–65%
• Adult females: 50–60%
• Infants: ~75%
• Main functions: transport, digestion, temperature regulation

Last verified on 23-06-2026

Explanation

• Rectified spirit contains about 95% ethyl alcohol.
• It is highly purified alcohol obtained by repeated distillation.
• The remaining percentage is usually water.
• It is used in pharmaceuticals, laboratories, and industrial processes.

Last verified on 23-06-2026

Explanation

• Hydrophytes have poorly developed roots.
• Because they live in water and can absorb water directly from their surroundings.

Additional information:

Key Characteristics of Hydrophytes:

• Reduced xylem tissue
• Large air spaces in tissues (aerenchyma)
• Thin or absent cuticle
• Flexible stems and leaves

Examples include water lily and Hydrilla.

Last verified on 23-06-2026