Explanation

• A rectifier is an electrical device that converts Alternating Current (AC) into Direct Current (DC).
• It allows current to flow in only one direction.
• It is commonly used in power supplies and chargers.
• Rectifiers use components like diodes for conversion.

Last verified on 25-06-2026

Explanation

When white light passes through a prism, it splits into 7 colors, forming a spectrum known as a rainbow:

1. Red
2. Orange
3. Yellow
4. Green
5. Blue
6. Indigo
7. Violet

The separation of visible light into its different colours is known as dispersion.

Last verified on 08-06-2026

Explanation

• Pressure in gases is due to the collision of gas molecules with the walls of the container.
• Gas molecules are in constant random motion.
• They continuously strike the container walls.
• These collisions create force per unit area (pressure).
• More collisions mean higher pressure.

Last verified on 08-06-2026

Explanation

• Short-sightedness is called Myopia.
• It is corrected by a concave lens.
• This lens is thin in the center and thick at edges.
• It helps light focus on the retina correctly.
• Without correction, distant objects look blurred.

Additional information:

• Long-sightedness is called Hypermetropia.
• It is corrected by a convex lens.
• This lens is thick in the center and thin at edges.
• It helps light focus on the retina properly.
• Without correction, near objects look blurred.

Last verified on 07-06-2026

Explanation

• Violet light has the smallest wavelength, approximately 380-450 nanometers (nm).
• While red light has the longest wavelength, approximately 620-750 nanometers (nm).
• The order of colors in the spectrum, from longest to shortest wavelength, is: Red, Orange, Yellow, Green, Blue, Indigo, Violet (ROYGBIV).

Last verified on 01-04-2026

Explanation

• Citric acid is a natural preservative found in many fruits, particularly in citrus fruits like lemons, oranges, and grapefruits.
• It's responsible for their sour taste and is also used as a food additive.
• Other fruits like mangoes, grapes, and strawberries also contain citric acid, although in smaller amounts.
• The presence of citric acid gives these fruits their characteristic sour taste.

Last verified on 16-03-2026

Explanation

• When light is focused in front of the retina, it creates a blurred image, indicating nearsightedness (myopia).
• This occurs because the eyeball is too long or the cornea is too steep.
• It causing light to focus before reaching the retina.

Last verified on 16-03-2026

Explanation

• Bases are substances that have a soapy or slippery feel when touched.
• This property occurs because bases react with oils on the skin, giving a soap-like texture.
• Many bases also turn red litmus paper blue in chemical tests.
• Common bases are used in cleaning agents, soaps, and detergents.

Last verified on 16-03-2026

Explanation

• The iris is the colored part of the eye that controls the size of the pupil.
• By adjusting the pupil size, it regulates the amount of light entering the eye, just like a camera diaphragm.
• Pupil dilation occurs in low light, letting in more light.
• Pupil contraction occurs in bright light, protecting the retina from damage.

Last verified on 15-03-2026

Explanation

• According to the Kinetic Molecular Theory, faster gas particles hit container walls more often.
• More frequent and stronger collisions increase the pressure.
• Higher temperature → higher particle speed → higher pressure.
• Pressure depends on number of collisions of gas molecules with container walls.
• Unit of gas pressure: Pascal (Pa).

Last verified on 13-03-2026