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
81
What is 'Absolute Zero' on the Celsius scale?
Answer:
-273.15°C
Absolute zero ($0 K$) is the theoretical temperature at which all molecular motion stops. On the Celsius scale, this corresponds to approximately -273.15°C.
82
The tendency of an atom to attract a shared pair of electrons towards itself is called:
Answer:
Electronegativity
Electronegativity is a chemical property that describes the power of an atom in a molecule to attract shared electrons to itself. Fluorine is the most electronegative element.
83
Which of these diseases is prevented by the BCG (Bacille Calmette-Guérin) vaccine?
Answer:
Tuberculosis
The BCG vaccine is primarily used against Tuberculosis (TB). It is often administered to infants and small children in countries where TB is common to protect them from severe forms of the disease, such as TB meningitis.
84
Which of the following is an example of an amorphous solid?
Answer:
Glass
Amorphous solids, like glass or plastic, lack a long-range periodic order in their atomic arrangement. Unlike crystalline solids (e.g., diamond or salt), they do not have a sharp melting point.
85
In Rutherford's gold foil experiment, why did most alpha particles pass straight through the foil?
Answer:
The atom is mostly empty space
Rutherford concluded that since the vast majority of alpha particles passed through the foil without deflection, the atom must consist mainly of empty space, with the mass concentrated in a tiny central nucleus.
86
What does the term 'asymptomatic carrier' mean in the context of infectious diseases?
Answer:
A person who is infected but shows no symptoms of the disease
An asymptomatic carrier is an individual who carries a pathogen and can transmit it to others but does not experience any symptoms themselves. This makes them 'silent' spreaders, as neither they nor those around them realize they are infected.
87
Which mode of transmission is responsible for spreading the Human Immunodeficiency Virus (HIV)?
Answer:
Exchange of infected body fluids
HIV is transmitted through specific body fluids, including blood, semen, vaginal fluids, and breast milk. Common routes include unprotected sexual contact, sharing contaminated needles, or from mother to child during childbirth or breastfeeding.
88
Which shell has the highest energy in an atom of Aluminum (Atomic No. 13)?
Answer:
M shell
The electron configuration of Aluminum is $2, 8, 3$. The electrons occupy the K ($n=1$), L ($n=2$), and M ($n=3$) shells. Since energy increases with the distance from the nucleus, the M shell has the highest energy.
89
Brownian motion provides evidence for:
Answer:
The existence of atoms and molecules in constant motion
Brownian motion is the random movement of particles suspended in a fluid resulting from their bombardment by fast-moving atoms or molecules in the gas or liquid.
90
Ringworm is a common skin infection characterized by a red, itchy, circular rash. What type of pathogen causes this condition?
Answer:
Fungus
Despite its name, ringworm is not caused by a worm; it is a fungal infection of the skin. Fungi called dermatophytes thrive on keratin, a protein found in skin, hair, and nails, leading to the characteristic circular lesions.