Explanation

• The longest cell in the human body is the nerve cell (neuron).
• Some neurons can extend up to 1 meter in length.
• They transmit impulses throughout the body.

Additional information:

• The smallest cell in the human body is the sperm cell (spermatozoon).
• It is measures approximately 4–5 micrometers (µm) in length.
• It is mainly consisting of a nucleus and a tail.

Last verified on 23-04-2026

Explanation

• A reflex action is a quick, automatic response to a stimulus.
• It is mainly controlled by the spinal cord, which is part of the central nervous system.
• This allows fast response without involving the brain immediately.
• Thus, reflexes are coordinated by the central nervous system.

Last verified on 23-04-2026

Explanation

• The kidney is an important organ responsible for filtering blood and forming urine.
• Its structural and functional unit is the nephron.
• Each kidney contains millions of nephrons.
• They perform filtration, reabsorption, and secretion.

Last verified on 23-04-2026

Explanation

• A barometer measures atmospheric (air) pressure.
• It helps in weather forecasting, detecting storms, and studying climate changes.
• Two common types of barometers: mercury barometer and aneroid barometer.

Last verified on 13-03-2026

Explanation

Bismuth is the only pure metal that expands when it solidifies (freezes).

Most substances contract on solidification, but bismuth behaves unusually—its solid form occupies a slightly larger volume than its liquid form.

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Explanation

To find the decimal equivalent of the binary number 1011:

(1 × 2³) + (0 × 2²) + (1 × 2¹) + (1 × 2⁰)

= (1 × 8) + (0 × 4) + (1 × 2) + (1 × 1)

= 8 + 0 + 2 + 1

= 11

Last verified on 12-04-2026

Explanation

• A covalent bond forms when atoms share electrons.
• It usually occurs between non-metals.
• Sharing helps atoms achieve stable electron configuration.
• No transfer of electrons occurs.
• Therefore, it is based on electron sharing.

Last verified on 12-04-2026

Explanation

• Refractive index shows how much light bends when entering a medium.
• Glass is a transparent solid with moderate optical density.
• Its refractive index is a standard value used in physics experiments.
• It is greater than water and less than diamond.
• So, the commonly accepted value for glass is around 1.5.

Last verified on 12-04-2026

Explanation

• A simple microscope is used to magnify small objects.
• It works by bending light to produce a larger image.
• Only a converging lens can produce a magnified virtual image.
• A convex lens has this property.
• Therefore, simple microscopes use a convex lens.

Last verified on 12-04-2026

Explanation

• Fission is the process of splitting an atomic nucleus into smaller nuclei, releasing a large amount of energy.
• It is used in nuclear power plants and atomic bombs.

Last verified on 12-04-2026