UPSC Essentials | Daily subject-wise quiz : Science and Technology MCQs on Uranium, Hydrogen as fuel and more (Week 130)

3. The biggest challenge in implementing hydrogen as fuel is its high density.

How many of the statements given above are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Explanation

— Hydrogen is appealing because it burns cleanly: when combined with oxygen in a fuel cell, it produces electricity and releases only water vapour as exhaust. Hence, statement 1 is correct.

— Unlike batteries, which must be recharged, hydrogen can be refueled quickly — much like petrol or diesel — making it attractive for long-haul trucks, buses, ships, and potentially even planes. Hence, statement 2 is not correct.

— And hydrogen isn’t just about cars. Properly harnessed, it could power homes, balance electricity grids, and store renewable energy from solar and wind farms for months at a time, smoothing out supply when the sun isn’t shining and the wind isn’t blowing. In principle, it could provide a backbone for a carbon-free society.

— The biggest challenge in implementing hydrogen as fuel is its low density. At room temperature, one kilogram of hydrogen would fill about 11 cubic meters — the size of a small bedroom. Petrol, by contrast, packs the same mass into just over a liter. Hence, statement 3 is not correct.

Therefore, option (a) is the correct answer.

QUESTION 2

Which of the following are fundamental forces of nature?

1. Electromagnetic force

2. Gravity force

3. Strong nuclear force

4. Weak nuclear force

Select the correct answer using the codes given below:

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2, 3 and 4

Explanation

— Electromagnetism is the fundamental force that unites electricity and magnetism.

— It is one of the four fundamental forces of nature – alongside gravity, the strong nuclear force, and the weak nuclear force. Unlike gravity, which only attracts, the electromagnetic force both attracts and repels.

— It governs the behaviour of charged particles, binding electrons to nuclei to form atoms and, in turn, molecules. Without it, chemistry would not exist, and neither would life.

Therefore, option (d) is the correct answer.

QUESTION 3

With reference to hypoxia and hypothermia, consider the following statements:

1. Hypoxia is caused by inadequate oxygen.

2. Hypothermia is a fall in core body temperature to a level where normal physical and brain functions are impaired.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Explanation

— A 13-year-old boy from Kunduz, Afghanistan, wanted to travel to Iran. So, he managed to sneak into an aircraft’s rear wheel well at the Kabul airport, except that the plane — operating Kam Air flight RQ4401 — was bound for Delhi, not Tehran. For the flight duration of over 90 minutes, the boy was in the wheel well, even as the aircraft cruised at over 30,000 feet where outside air pressure and temperature plummet. Miraculously, he survived the ordeal, landing seemingly unharmed at the Delhi airport, where he was spotted by some airport staff. In the evening, he was sent back on the same aircraft to Kabul, this time in the plane’s passenger cabin.

Inside the wheel well of an aircraft

— Hypoxia is caused by inadequate oxygen, while hypothermia is a fall in core body temperature to a level where normal physical and brain functions are impaired. Severe levels of either can lead to unconsciousness, and even death. Hence, statements 1 and 2 are correct.

Therefore, option (c) is the correct answer.

QUESTION 4

With reference to Uranium, consider the following statements:

1. It is the most common fissile material.

2. More than 99 per cent of naturally occurring uranium is U-235.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Explanation

— Uranium is the most common fissile material used in these processes, either to make electricity in civilian reactors or in weapons. Hence, statement 1 is correct.

— But naturally occurring uranium is not fissile, meaning its nucleus is relatively stable and does not readily break up into nuclei of smaller elements.

— Naturally occurring uranium is primarily U-238, a slightly heavier isotope of the element. It is the slightly lighter uranium, called U-235, which is fissile. More than 99 per cent of naturally occurring uranium is U-238. Hence, statement 2 is not correct.

— Enrichment is the process of increasing the concentration of U-235 in a uranium sample.

Therefore, option (a) is the correct answer.

QUESTION 5

With reference to the AstroSat, consider the following statements:

1. It is India’s first multi wavelength space observatory dedicated for astronomy.

2. It was launched aboard the PSLV-C30.

3. It is capable of observing the universe simultaneously in a broad energy range from ultraviolet (UV) rays.

How many of the statements given above are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Explanation

— On September 28, 2025 AstroSat India’s first multi wavelength space observatory dedicated to astronomy, completed a decade filled with groundbreaking discoveries and dedicated service to the global scientific community. Hence, statement 1 is correct.

— AstroSat was launched aboard the PSLV-C30 on September 28, 2015 from the Satish Dhawan Space Centre. Hence, statement 2 is correct.

— AstroSat is capable of observing the universe simultaneously in a broad energy range from ultraviolet (UV), visible, and high energy X-rays, rendering it a powerful tool for understanding various cosmic phenomena. Hence, statement 3 is correct.

Therefore, option (c) is the correct answer.

(Source: www.isro.gov.in)

Previous Daily Subject-Wise-Quiz

Daily Subject-wise quiz — History, Culture, and Social Issues (Week 125)

Daily subject-wise quiz — Polity and Governance (Week 130)

Daily subject-wise quiz —  Science and Technology (Week 129)

Daily subject-wise quiz — Economy (Week 129)

Daily subject-wise quiz — Environment and Geography (Week 129)

Daily subject-wise quiz – International Relations (Week 129)

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