Correct Answer: 216 seconds

Solution : Given: A train 1800 m long, travelling at the speed of 30 km/hr.
Convert km/hr into m/s by multiplying it with $\frac{5}{18}$.
⇒ 30 km/hr = 30 × $\frac{5}{18}$ = $\frac{25}{3}$ m/s
Now, $\text{Time}=\frac{\text{Distance}}{\text{Speed}}$
So, the time in which a train passes a signal pole $=\frac{1800}{\frac{25}{3}}=\frac{1800\times 3}{25}=216$ seconds
Hence, the correct answer is 216 seconds.

Correct Answer: 12.5%

Solution : Let's the cost price of the desktop as $C$, the profit as $P$, and the selling price as $S$
Selling Price = Cost Price + Profit
⇒ $S = 9P$
⇒ $C + P = 9P$
⇒ $C = 8P$
So, Profit % = $\frac{Profit}{Cost Price}$×100  = $\frac{P}{8P}$ ​×100 = 12.5%
Hence, the correct answer is 12.5%.

Correct Answer: Conversion of neutrons into protons

Solution : The correct answer is the Conversion of neutrons into protons.

The release of an enormous amount of energy in an atomic bomb explosion is caused by the conversion of neutrons into protons. When a neutron collides with the nucleus of an atom of uranium-235 or plutonium-239, it splits the nucleus into two fragments. Each of these fragments is a nucleus with about half of the protons and neutrons of the original nucleus.

Correct Answer: autoradiography

Solution : The correct answer is autoradiography.

One technique used to trace radioactive elements in living cells is autoradiography. Autoradiography is a method that involves exposing a photographic film, or other detector to a specimen containing radioactive isotopes. The emitted radiation exposes the film, creating a pattern that corresponds to the distribution of the radioactive substance in the specimen.

Correct Answer: Law and Justice

Solution : The correct answer is Law and Justice.

The Election Laws (Amendment) Bill 2021 belongs to the Law and Justice Ministry of India. This bill seeks to link electoral rolls with Aadhaar to remove fake voters from the list. This ministry is in charge of managing legislative and legal issues, such as changes to election laws and other relevant rules.

Correct Answer: fires in California is

Solution : The error lies in the third option.

The subject fires is plural, so the verb should also be plural to maintain subject-verb agreement. In the original sentence, is (singular) is used instead of are (plural). The corrected version ensures subject-verb agreement by using the plural form are to match the plural subject fires.

Therefore, the correct sentence should be: "Fires in California are sounding alarm bells that cannot be ignored."

Correct Answer: I am willing to consider the possibility

Solution : The correct choice is the first option.

• The sentence with no spelling error is: I am willing to consider the possibility.
• The second option contains the incorrect spelling "considerr", whereas the correct spelling is consider.
• The third and fourth options contain the incorrect spelling "posibility" whose correct spelling is possibility.

Correct Answer: Magnesium

Solution : The correct option is Magnesium.

The chlorophyll pigment is present in cell organelles known as chloroplasts. These chloroplasts serve as a site for photosynthesis. Chlorophyll is a porphyrin derivative. It has a magnesium atom in the centre, and four nitrogen atoms surround it. A pyrrole ring structure with four carbons and nitrogen exists in the chlorophyll.

Correct Answer: Temple entry movement

Solution : The correct option is Temple entry movement.

In 1927, B. R. Ambedkar initiated the Temple entry movement to fight against caste-based discrimination. It aimed to secure the right of Dalits to enter Hindu temples, challenging the prevailing social norms. Ambedkar's efforts laid the foundation for social equality and Dalit rights in India's struggle against untouchability and caste-based discrimination.

Correct Answer:

Solution : According to the given figures –
1. The × sign moves two spaces (each space is equal to half-a-side of the square boundary) and one space anticlockwise alternately.
2. The ÷ sign moves one space (each space is equal to half-a-side of the square boundary) and two spaces anticlockwise alternately.

Therefore, the figure in the second option is the required figure. Hence, the second option is correct.