Explanation

• Chlorination is the process of adding disinfectants, such as chlorine, to water to kill harmful microorganisms.
• It prevent the spread of waterborne diseases.

Explanation

The average distance from the Earth to the Sun is approximately 150 million kilometers.

It is also called 1 astronomical unit (or AU).

Explanation

Vitamin B is found in:

• Vegetables (like leafy greens, bell peppers, and mushrooms)
• Whole wheat grains (like brown rice, quinoa, and whole-wheat bread)
• Fresh meat (like beef, chicken, and fish)

Vitamin B is a complex of several B vitamins, including:

• B1 (Thiamin)
• B2 (Riboflavin)
• B3 (Niacin)
• B5 (Pantothenic acid)
• B6 (Pyridoxine)
• B7 (Biotin)
• B9 (Folic acid)
• B12 (Cobalamin)

Explanation

Fats are found in various food sources, including:

• Oil (such as olive oil, coconut oil, etc.)
• Butter
• Margarine
• Seeds (such as sunflower seeds, pumpkin seeds, etc.)
• Nuts (such as almonds, walnuts, etc.)

Explanation

The human eye is most sensitive to yellow-green in sunlight.

The sensitivity of the human eye to light of a given intensity varies widely over the wavelength range of 380-800 nm.

Explanation

A dipole in an electric field behaves in two ways:

• In a uniform electric field:

The two equal and opposite forces cancel each other out.

So, the net force on the dipole is zero.

But a torque is produced that tends to align the dipole moment parallel to the electric field.

• In a non-uniform electric field:

The dipole does experience a net force, and that force is generally not simply parallel to the field.

So the correct answer remains:

(D) None of these — because in a uniform electric field, the net force on a dipole is zero.

Option (C) would be correct only if we were talking about torque direction or net force in a non-uniform field.

Explanation

The drum of a Photostat machine (also known as a xerox machine) is made of a material called selenium,

That is a photoconductive element.

This means that when exposed to light

It becomes conductive, allowing the machine to transfer the image onto the paper. 

Explanation

Salt and water can be recovered from an aqueous salt solution by the process of evaporation.

Explanation

We are given:
A wire with resistance R = 6 Ω
It is cut into two equal parts
These two parts are then connected in parallel

Step 1:

Resistance of each half
When a wire is cut into two equal parts, the resistance of each half becomes half:
Rhalf​=6/2​=3Ω

Step 2:

Two 3 Ω resistors in parallel
Use the formula for two resistors in parallel:
Req​1​=1/3​+1/3​=2/3​

Req​=3/2​=1.5Ω

Explanation

The wavelength of the audible frequency (20 Hz to 20 kHz) audible to the human ear is approximately 17 m to 17 mm.

Bats use slightly higher frequencies, so they can solve targets smaller than 17mm.

The wavelength of audible sound is much longer than the wavelength of visible light.