General Science/Everyday Science MCQs
Topic Notes: General Science/Everyday Science
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
1
Which state of matter consists of ionized gas with free-moving electrons and positive ions?
Answer:
Plasma
Plasma is often called the fourth state of matter. It is formed at very high temperatures where atoms are stripped of their electrons, resulting in a soup of ions and electrons that conducts electricity.
2
If a doctor prescribes a 7-day course of antibiotics, why is it dangerous for the patient to stop after 3 days when they feel better?
Answer:
The most resistant bacteria may survive and multiply, leading to a relapse and resistance
Feeling better usually means the 'weakest' bacteria have died. If treatment stops early, the 'stronger' bacteria that are still alive have a chance to recover, mutate, and potentially develop resistance, making the next infection much harder to cure.
3
Which state of matter has neither a definite shape nor a definite volume?
Answer:
Gas
Gases expand to fill the shape and volume of whatever container they are in because the intermolecular forces between gas particles are negligible.
4
What type of immunity is acquired when a person's own immune system produces antibodies after receiving a vaccination?
Answer:
Artificial Active Immunity
Active immunity occurs when the body produces its own antibodies. When this is triggered by a medical intervention like a vaccine rather than a natural infection, it is classified as artificial active immunity. This provides long-term protection through memory cells.
5
Which state of matter is characterized by having a definite shape and a definite volume?
Answer:
Solid
Solids have a definite shape and volume because their particles are closely packed in a fixed, regular pattern. The intermolecular forces are strong enough to keep the particles from moving past one another, allowing only for vibration around fixed positions.
6
Mendeleev's Periodic Table had some gaps; he predicted the existence of an element he called 'Eka-Aluminum', which was later discovered as:
Answer:
Gallium
Mendeleev predicted the properties of 'Eka-Aluminum' (below Aluminum). When Gallium was discovered in 1875, its properties matched his predictions almost perfectly, which validated his periodic table.
7
What is the name of the vertical columns in the periodic table?
Answer:
Groups
Vertical columns in the periodic table are called groups (or families). Elements in the same group have the same number of valence electrons and similar chemical properties.
8
Which of the following is an example of 'Artificial Passive Immunity'?
Answer:
Injection of antivenom after a snake bite
When a person receives an injection of antibodies produced in another organism (like antivenom or immunoglobulin), it is artificial passive immunity. It provides immediate but temporary protection because the body doesn't learn to make the antibodies itself.
9
What is an 'Antigen'?
Answer:
A substance (usually a protein) that the immune system recognizes as foreign and triggers an immune response
Antigens are the 'identity tags' on the surface of cells or viruses. When your immune system sees a 'foreign' antigen (like one on a bacterium or in a vaccine), it produces antibodies that are custom-shaped to fit that specific tag.
10
What determines the identity of an element?
Answer:
The number of protons
The atomic number, which is the number of protons in the nucleus of an atom, uniquely identifies an element. No two different elements have the same number of protons.