Explanation

LCM of 4 and 10: multiples of 4 = 4, 8, 12, 16, 20... multiples of 10 = 10, 20...

First common multiple = 20 

Last verified on 12-04-2026

Explanation

• Standing Wave is formed by the superposition of two identical waves.
• These waves have same frequency, amplitude, and wavelength.
• They move in opposite directions.
• This results in fixed nodes and antinodes.

Last verified on 11-04-2026

Explanation

AND Gate Rule:

• Output = 1 (HIGH) only when all inputs are 1 (HIGH)
• Truth condition: A = 1 AND B = 1 → Output = 1

Last verified on 11-04-2026

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

• Every element is identified by the number of protons in its nucleus.
• This number determines the identity of the element.
• It is written as Z in chemistry.
• It is always equal to the number of electrons in a neutral atom.
• This is called the atomic number.

Last verified on 12-04-2026

Explanation

• Radioactive substances decay over time in a predictable pattern.
• The time required for half of the radioactive nuclei to decay is a standard measure.
• It is used to compare stability of different radioactive elements.
• This concept is widely used in nuclear physics and medicine.
• It is called the half-life of a substance.

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

• Ohm’s law states that current is directly proportional to voltage when temperature is constant.
• It describes the relationship between voltage, current, and resistance.
• The correct mathematical form is V = IR.
• Here V = voltage, I = current, R = resistance.
• It is a fundamental law of electricity.

Last verified on 12-04-2026

Explanation

• When pressure is constant, the volume of a gas changes directly with temperature (in Kelvin).
• As temperature increases, gas particles move faster and occupy more space.
• This relationship is used to describe gas expansion.
• It applies only at constant pressure conditions.
• This is known as Charles’s Law.

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