General Knowledge MCQs for PPSC, FPSC & Competitive Exams (Free PDF)

This question tests knowledge of foam fire extinguishers. The correct answer is Aqueous Film Forming Foam (AFFF), which is widely used in foam extinguishers to suppress fires involving flammable liquids.

AFFF forms a thin film over the surface of burning fuel, cutting off the oxygen supply, cooling the fire, and preventing the release of flammable vapours. It is especially effective against Class B fires, such as those involving petrol, diesel, and other flammable liquids.

• Nitrous Oxide: Used as an anaesthetic and oxidizer, not in fire extinguishers.
• Methane: A flammable gas and not a firefighting agent.
• AFFF: The standard foaming agent used in foam fire extinguishers.
• Carbon Monoxide: A poisonous gas with no use as a fire-extinguishing foam.

Therefore, the correct answer is: Aqueous Film Forming Foam (AFFF).

The correct answer is Thermodynamics. A refrigerator operates based on the principles of thermodynamics, specifically the second law, which dictates the direction of heat flow. Refrigerators use a refrigeration cycle to transfer heat from a colder space (inside the fridge) to a warmer space (the room), which requires work input, typically from a compressor. This process is a direct application of thermodynamic principles. Conservation of Mass, Electromagnetism, and Newton's Laws are fundamental physics concepts but do not directly describe the primary mechanism of heat transfer and cooling in a refrigerator.

Carbon Dioxide is the primary greenhouse gas responsible for increased global temperatures, a phenomenon known as global warming. It traps heat in the Earth's atmosphere, largely due to human activities like burning fossil fuels.

• Oxygen is vital for respiration but does not contribute to the greenhouse effect.
• Hydrogen is not a significant atmospheric gas contributing to global warming.
• Nitrogen is the most abundant gas in the atmosphere but is largely inert and does not trap heat.

Understanding the role of greenhouse gases is fundamental to comprehending climate change.

Earth is the only planet in our solar system where free oxygen (O2) is abundantly available in the atmosphere. This is primarily due to the process of photosynthesis carried out by plants and algae over billions of years, which releases oxygen as a byproduct.

• Mars has a very thin atmosphere composed mostly of carbon dioxide, with only trace amounts of oxygen.
• Jupiter is a gas giant with an atmosphere primarily of hydrogen and helium, lacking free oxygen.
• Venus has a dense atmosphere dominated by carbon dioxide, with virtually no free oxygen.

The presence of free oxygen is a key indicator of life as we know it.

Insulin is a crucial hormone secreted by the Pancreas. Specifically, it is produced by the beta cells within the islets of Langerhans in the pancreas. Insulin plays a vital role in regulating blood glucose levels by facilitating the uptake of glucose into cells for energy or storage.

• The Adrenal gland produces hormones like adrenaline and cortisol, involved in stress response.
• The Pituitary gland is the 'master gland' that regulates many other endocrine glands but does not produce insulin.
• The Thyroid gland produces hormones that regulate metabolism and growth.

Dysfunction in insulin production or action leads to diabetes.

Mount Tambora, renowned for its catastrophic 1815 eruption, one of the largest in recorded history, is located in Indonesia. This active stratovolcano is situated on Sumbawa island, part of the Indonesian archipelago. Its eruption had significant global climate impacts, leading to the 'Year Without a Summer' in 1816.

• The Philippines is home to volcanoes like Mount Pinatubo, but not Tambora.
• Japan features iconic volcanoes such as Mount Fuji, but Tambora is not located there.
• Malaysia is not known for major active volcanoes like Tambora.

Indonesia's location on the Pacific Ring of Fire makes it highly volcanically active.

The program launched by Pakistan for science and development in 2025 is STED 2025. This refers to the Science, Technology, and Economic Development (STED) initiative, a strategic framework aimed at fostering innovation, research, and technological advancement within the country to drive economic growth and societal progress.

• NASA 2025 is incorrect as NASA is the U.S. space agency, not a Pakistani program.
• Science Leap 2025 is a plausible but incorrect name for the specific Pakistani initiative.
• Digital Pakistan Plus, while related to national development, is not the specific science and development program in question for 2025.

National policies like STED 2025 are crucial for a country\'s future.

Pakistan received $8 billion in remittances during the first quarter of 2025. Remittances, which are funds sent by expatriate workers to their home country, are a vital source of foreign exchange for Pakistan, significantly contributing to its economy and balance of payments. This figure reflects the ongoing financial contributions from the Pakistani diaspora.

• $12 billion, $16 billion, and $22 billion are incorrect figures for the specified period.

Accurate economic data like this is essential for understanding a nation\'s financial health and global economic interactions.

The correct answer is Ahmed al-Sharaa. Following the collapse of the Bashar al-Assad regime in December 2024, Ahmed al-Sharaa, the leader of Hay'at Tahrir al-Sham (HTS), emerged as a prominent figure in the transitional government in Syria. He assumed a de facto leadership role, marking a significant shift in the country's political landscape.

• Bashar al-Assad is incorrect because he was overthrown in December 2024, ending his long rule.
• Hassan Nasrallah is incorrect; he is the leader of Hezbollah, a Lebanese political party and militant group, not a Syrian president.
• Najib Mikati is incorrect; he is the current Prime Minister of Lebanon, not a Syrian leader.

The correct answer is 145%. This figure represents a significant escalation in the trade tensions between the U.S. and China. The U.S. government, under specific administrations, implemented a series of tariffs on various Chinese goods, citing unfair trade practices and intellectual property theft. The 145% tariff was a peak rate applied to certain categories of imports as part of these escalating measures.

• 45% is incorrect as it was a lower rate applied to some goods but not the highest or the one resulting from the series of increases.
• 100% is incorrect; while high tariffs were imposed, 100% was not the specific peak rate mentioned in this context.
• 200% is incorrect; although some tariffs were very high, 200% was not the widely reported maximum percentage resulting from the series of increases on Chinese goods.