The correct answer is: (b) Vitamin C

Explanation:

• Vitamin C, also known as ascorbic acid, is an essential nutrient that plays a vital role in the body.
• It is known for its antioxidant properties, which help in neutralizing free radicals and protecting cells from damage.
• Vitamin C is crucial for the synthesis of collagen, a protein that helps maintain skin, blood vessels, and tissues. It also enhances iron absorption and supports the immune system.

Information Booster:

• It is a water-soluble vitamin crucial for immune health and wound healing.

• Vitamin C helps the body absorb iron and is vital for the production of collagen.

• Citrus fruits, berries, and leafy greens are rich sources of Vitamin C.

• A deficiency in Vitamin C can lead to scurvy, a condition characterized by fatigue, swollen gums, and joint pain.

Additional Knowledge:

• Vitamin A: Vitamin A is a fat-soluble vitamin that plays a crucial role in vision, immune function, and skin health. It is found in two primary forms: preformed vitamin A (found in animal products) and provitamin A (such as beta-carotene, found in plant-based foods like carrots).
• Vitamin D: Vitamin D is a fat-soluble vitamin that helps regulate calcium and phosphate in the body, promoting healthy bones and teeth. It can be synthesized by the skin when exposed to sunlight, and is also found in foods like fatty fish, fortified dairy products, and egg yolks.
• Vitamin K: Vitamin K is crucial for blood clotting and bone health. It exists in two primary forms: K1 (phylloquinone), found in green leafy vegetables, and K2 (menaquinone), found in fermented foods and animal products.

Given: XPC, QHT, JZK, CRB, ?

Logic: 1st letter - 7, 2nd letter - 8 and 3rd letter - 9 place.

For, 1st letter

X - 7 → Q, Q - 7 → J, J - 7 → C, C - 7 → V

For, 2nd letter

P - 8 → H, H - 8 → Z, Z - 8 → R, R - 8 → J

For, 3rd letter

C - 9 → T, T - 9 → K, K - 9 ​→ B, B - 9 → S

So, the missing term is VJS.

Thus, correct option is (d).

Correct Answer is: Only conclusion III follows.

Statements:

1. All D are E.

2. Some E are F.

From the given statements possible Venn diagram will be.

Conclusions:

I. All D are F. (False, there is no direct relation between D and F).

II. Some F are D. (False, there is no direct relation between F and D).

III. Some F are E. (True, there is direct relation between F and E).

Only conclusion III follows.

Thus, correct option is (c).

The correct answer is: (c) Acoustics

Explanation:

The study of sound and sound waves is known as Acoustics. It is a branch of physics that deals with:

• Production,
• Transmission, and
• Effects of sound waves in various media such as air, water, and solids.

Acoustics helps in understanding not just how sound travels, but also how it can be controlled and used in real-world applications, like in architecture, music, sonar, medical imaging (ultrasound), and even noise control.

Information Booster:

The term “acoustics” comes from the Greek word akoustikos, meaning “of or for hearing.”

Applications of acoustics include:

• Designing concert halls and auditoriums
• Noise cancellation technologies
• Ultrasonic cleaning and imaging
• Seismology (study of Earth’s vibrations)

The correct answer is option (c) Virat Kohli.

Explanation

On May 12, 2025, Virat Kohli, one of India's most celebrated cricketers, announced his retirement from Test cricket at the age of 36. His decision came shortly after former captain Rohit Sharma also retired from the format, marking a significant transition period for Indian cricket.

Career Highlights:

· Test Debut: June 20, 2011, against the West Indies.

· Total Test Matches: 123

· Total Runs: 9,230

· Batting Average: 46.85

· Centuries/Half-Centuries: 30/31

· Highest Score: 254*

· Captaincy Tenure: 2014–2022

· Matches as Captain: 68

· Wins as Captain: 40

Kohli's leadership transformed India's Test team into a formidable force, especially in overseas conditions. Under his captaincy, India achieved its first-ever Test series win in Australia during the 2018–19 tour. He also led India to the finals of the World Test Championship in both 2021 and 2023.

Correct Answer is: Both (i) and (iii) follows.

Statement:

Tonight, if I knead the dough, along with yeast and sugar, for my doughnuts, I will be able to bake and serve them fresh to my guest tomorrow evening.

Courses of Action:

(i) I must make arrangements to prevent the dough from getting spoilt and give good baking results. (True, since the dough is being prepared in advance, it needs proper storage (like refrigeration) to avoid spoiling).

(ii) I must cancel on my guest for tomorrow. (False, the statement does not suggest any reason to cancel the guest. In fact, the plan is to serve fresh doughnuts to the guest).

(iii) I must follow my doughnut recipe properly and bake them at the right temperature. (True, to get good results, following the recipe and baking correctly is necessary).

Both (i) and (iii) follows.

Thus, correct option is (d).

​The correct answer is (d) Silicon

Explanation:

• Silicon (Si) is the most widely used material for manufacturing solar cells because of its abundant availability, semiconductor properties, and high efficiency in converting sunlight into electricity.
• It acts as a semiconductor, allowing it to absorb sunlight and generate electricity through the photovoltaic effect.
• Silicon-based solar panels are durable, cost-effective, and widely used in residential, commercial, and industrial applications.

Information Booster:

Why is Silicon Preferred for Solar Cells?

1. Abundant Availability: Silicon is the second most abundant element on Earth.
2. Efficient Semiconductor: It effectively converts sunlight into electricity.
3. Durability: Silicon-based solar panels can last 25+ years with proper maintenance.
4. Cost-Effective: Silicon solar cells are mass-produced, making them affordable.

How Solar Cells Work?

1. Sunlight (photons) strikes the silicon-based solar cell.
2. Electrons get excited and move, creating an electric current.
3. This electricity is collected and used to power electrical devices.

Types of Silicon Solar Cells:

1. Monocrystalline Silicon (Mono-Si): High efficiency, expensive.
2. Polycrystalline Silicon (Poly-Si): Moderate efficiency, affordable.
3. Amorphous Silicon (a-Si): Lower efficiency, flexible panels.

The correct answer is (c) C₂H₄.

Explanation:

An unsaturated compound contains one or more double or triple bonds between carbon atoms. In this case, C₂H₄ is ethene (ethylene), which is an unsaturated compound because it contains a double bond between the two carbon atoms.

On the other hand:

• C₂H₆ is ethane, which is a saturated compound because it contains only single bonds.
• C₃H₈ is propane, also a saturated compound with only single bonds.
• C₄H₁₀ is butane, which is also a saturated compound with only single bonds.

Information Booster:

• Unsaturated compounds are those that contain double or triple bonds between carbon atoms.
• Saturated compounds contain only single bonds between carbon atoms.
• Ethene (C₂H₄) is a simple alkene, which is an unsaturated hydrocarbon.
• The double bond in ethene allows it to react with other molecules, making it reactive compared to saturated hydrocarbons.
• Unsaturation in organic compounds can be identified by the presence of double or triple bonds between carbon atoms, as opposed to single bonds in saturated compounds.

Additional Knowledge:

• (a) C₂H₆: Ethane is a saturated compound with only single bonds between carbon atoms.
• (b) C₃H₈: Propane is a saturated compound with only single bonds.
• (d) C₄H₁₀: Butane is a saturated compound with only single bonds.