General Science - MCQ Practice Questions

At maximum height, v = 0. Using v² = u² - 2gh: 0 = 20² - 2(10)h. 20h = 400. h = 20 m.

For capacitors in series: 1/C = 1/C₁ + 1/C₂ = $\frac{1}{2}$ + $\frac{1}{3}$ = $\frac{5}{6}$. Therefore C = $\frac{6}{5}$ = 1.2 μF.

Refractive indices: Air ≈ 1, Water ≈ 1.33, Glass ≈ 1.5, Diamond ≈ 2.42. Diamond has the highest refractive index among these options.

Centripetal acceleration a = v²/r = (10)²/5 = $\frac{100}{5}$ = 20 m/s².

Charge Q = I × t, where I = 5 A and t = 10 s. Q = 5 × 10 = 50 Coulombs.

The Lyman series involves transitions to n=1 from higher energy levels. Balmer series ends at n=2, Paschen at n=3, and Brackett at n=4.

This problem requires using Newton's Second Law to find acceleration, then applying kinematic equations to determine final velocity.

Step 1: Find the Acceleration Using Newton's Second Law

Newton's Second Law states that the net force equals mass times acceleration. We need to rearrange to solve for acceleration.

Step 2: Apply the Kinematic Equation to Find Final Velocity

Since the object starts from rest (initial velocity = 0) and travels a distance of 5 m with constant acceleration, we use the equation that relates velocity, acceleration, and distance.

The velocity after traveling 5 m is 5√2 m/s (≈ 7.07 m/s). The answer is (A).

Understanding:

We need to identify the disease caused by Vitamin C deficiency.

Step 1: Matching vitamins to deficiency diseases

Each vitamin deficiency leads to a specific disease:

Step 2: Identifying Scurvy

Scurvy is caused by a lack of Vitamin C (ascorbic acid). It is characterized by swollen and bleeding gums, weakness, anaemia, and skin haemorrhages. Vitamin C is essential for collagen synthesis, which maintains the integrity of blood vessels and connective tissue.

Answer:

The disease caused by Vitamin C deficiency is Scurvy.

Quick Tip:

A helpful mnemonic — 'C for Citrus, C for Scurvy': sailors historically suffered from scurvy due to lack of fresh fruits during long voyages.

Understanding:

We need to identify the microorganism responsible for causing Tuberculosis.

Step 1: Identifying the causative agents of common diseases

Step 2: About Mycobacterium tuberculosis

Tuberculosis is a highly contagious airborne disease primarily affecting the lungs. It is caused by the bacterium Mycobacterium tuberculosis, discovered by Robert Koch in 1882. It spreads through respiratory droplets when an infected person coughs or sneezes.

Answer:

The causative agent of Tuberculosis is Mycobacterium tuberculosis.

Quick Tip:

Robert Koch discovered M. tuberculosis on 24 March 1882 — this date is now celebrated as World Tuberculosis Day.

Understanding:

We need to identify the organ affected by Cirrhosis.

Step 1: Understanding Cirrhosis

Cirrhosis is a chronic liver disease in which normal liver tissue is replaced by scar tissue (fibrosis), severely impairing liver function. Common causes include chronic alcoholism, hepatitis B and C infections, and non-alcoholic fatty liver disease.

Step 2: Ruling out other options

None of these are associated with Cirrhosis.

Answer:

Cirrhosis is a disease that affects the Liver.

Quick Tip:

Cirrhosis is an irreversible condition — the scarred liver tissue cannot regenerate, making early diagnosis and lifestyle changes critical.

Understanding:

We need to identify the mosquito species that transmits Dengue fever.

Step 1: Mapping mosquito species to diseases

Step 2: About Dengue transmission

Dengue is a viral disease caused by the Dengue virus (DENV), which belongs to the Flavivirus genus. It is spread primarily by the female Aedes aegypti mosquito, which typically bites during the day. Dengue is characterised by high fever, severe headache, pain behind the eyes, joint and muscle pain, and rash.

Answer:

Dengue is transmitted by the Aedes aegypti mosquito.

Quick Tip:

Aedes aegypti mosquitoes breed in stagnant, clean water stored in containers, flower pots, and tyres — eliminating such breeding sites is the primary prevention strategy.

Understanding:

We need to identify the disease among the given options that is not caused by a virus.

Step 1: Classifying the diseases by causative agents

Step 2: Identifying the non-viral disease

Cholera is a bacterial infection caused by Vibrio cholerae. It spreads through contaminated water and food, causing severe watery diarrhoea and dehydration. The other three diseases in the list are all caused by viruses.

Answer:

Cholera is the disease that is NOT caused by a virus — it is caused by the bacterium Vibrio cholerae.

Quick Tip:

Cholera is a water-borne disease — the key prevention strategy is access to clean drinking water and proper sanitation, not vaccination (unlike the other viral diseases listed).

Understanding:

We need to identify the hormone primarily responsible for regulating blood glucose (sugar) levels.

Step 1: Role of each hormone

Step 2: Why Insulin is correct

Insulin is the primary hormone that regulates blood glucose. When blood sugar rises after a meal, the pancreas secretes insulin, which facilitates the uptake of glucose by body cells and its storage as glycogen in the liver. Deficiency or resistance to insulin leads to Diabetes Mellitus.

Answer:

Insulin is the hormone directly responsible for regulating blood sugar levels.

Quick Tip:

Insulin lowers blood sugar (anabolic), while Glucagon (also from the pancreas) raises blood sugar — they act as antagonists to maintain glucose homeostasis.

Understanding:

We need to identify the full form of the BCG vaccine used against Tuberculosis.

Step 1: Historical background of BCG

The BCG vaccine was developed by French bacteriologists Albert Calmette and Camille Guérin at the Pasteur Institute. They created a weakened (attenuated) strain of Mycobacterium bovis to develop immunity against Tuberculosis.

Step 2: Full form

BCG stands for Bacillus Calmette-Guérin, named after its two developers. It is one of the oldest and most widely used vaccines in the world and is part of India's Universal Immunisation Programme (UIP), given to newborns.

Answer:

BCG stands for Bacillus Calmette-Guérin.

Quick Tip:

The BCG vaccine was first used in humans in 1921. In India, it is administered at birth as part of the national immunisation schedule to protect against severe forms of TB in children.

Understanding:

We need to identify the disease caused by the protozoan Plasmodium vivax.

Step 1: Mapping protozoans to diseases

Step 2: About Plasmodium vivax and Malaria

Plasmodium vivax is one of four species of Plasmodium that causes malaria in humans (others: P. falciparum, P. malariae, P. ovale). It causes Benign Tertian Malaria, where fever recurs every 48 hours. Malaria is transmitted by the bite of the female Anopheles mosquito.

Answer:

Malaria is the disease caused by the protozoan Plasmodium vivax.

Quick Tip:

Among the Plasmodium species, P. falciparum causes the most severe and potentially fatal form of malaria — Malignant Tertian Malaria — and is responsible for the majority of malaria deaths globally.

Understanding:

We need to identify what Haemophilia is and how it affects the body.

Step 1: Understanding Haemophilia

Haemophilia is a hereditary (genetic) bleeding disorder in which the blood does not clot properly. It occurs due to the deficiency or dysfunction of specific clotting factors — Factor VIII in Haemophilia A (most common) and Factor IX in Haemophilia B. As a result, even minor injuries can lead to prolonged bleeding.

Step 2: Ruling out other options

Step 3: Genetic nature

Haemophilia is an X-linked recessive disorder. It predominantly affects males, while females are usually carriers. The gene responsible for the clotting factors is located on the X chromosome.

Answer:

Haemophilia is characterised by the inability of blood to clot normally due to deficiency of clotting factors.

Quick Tip:

Haemophilia is often called the 'Royal Disease' because it spread through the royal families of Europe, descended from Queen Victoria, who was a carrier.

Understanding:

We need to identify which vitamin is produced in the human skin when it is exposed to sunlight.

Step 1: The process of Vitamin D synthesis

When ultraviolet B (UVB) radiation from sunlight falls on the skin, it converts a cholesterol derivative (7-dehydrocholesterol) present in the skin into Vitamin D3 (cholecalciferol). This is then processed by the liver and kidneys into its active hormonal form, calcitriol.

Step 2: Role of Vitamin D

Vitamin D is essential for the absorption of calcium and phosphorus in the intestine, which is critical for bone mineralisation and strength. Deficiency of Vitamin D leads to Rickets in children and Osteomalacia in adults.

Step 3: Why other vitamins are incorrect

Answer:

Vitamin D is the vitamin synthesised in the human skin upon exposure to sunlight.

Quick Tip:

Vitamin D is unique in that it functions both as a vitamin (obtained from diet) and as a hormone (synthesised by the body). It is the only vitamin the body can produce on its own from non-food sources.

Understanding:

We need to identify which greenhouse gas has the highest Global Warming Potential (GWP) over a 100-year time horizon among the given options.

Step 1: Define GWP

Global Warming Potential is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific period, relative to carbon dioxide (GWP = 1).

Step 2: Compare GWP values of listed gases

Step 3: Identify the correct answer

Sulphur hexafluoride has by far the highest GWP among the options listed, making it the most potent greenhouse gas per unit mass.

Answer:

Sulphur hexafluoride (SF₆) has the highest Global Warming Potential over a 100-year period among the given options.

Quick Tip:

SF₆ is widely used in electrical switchgear and transformers. Despite being released in small quantities, its extremely high GWP and long atmospheric lifetime make it a significant concern for climate change.

Understanding:

We need to identify the Indian state where the Chipko Movement originated.

Step 1: Historical context of the Chipko Movement

The Chipko Movement (meaning 'to hug' or 'to cling') was a non-violent environmental movement in which villagers, especially women, hugged trees to prevent them from being felled by logging contractors.

Step 2: Location of origin

The movement began in 1973 in the Chamoli district of what was then Uttar Pradesh — the region is now part of the state of Uttarakhand (formed in 2000). The key figures associated with the movement include Sundarlal Bahuguna, Gaura Devi, and Chandi Prasad Bhatt.

Step 3: Eliminate other options

Answer:

The Chipko Movement originated in Uttarakhand (formerly part of Uttar Pradesh).

Quick Tip:

The Chipko Movement is considered one of the earliest and most successful grassroots environmental movements in India and inspired similar forest conservation efforts worldwide.

Understanding:

We need to identify the atmospheric layer that contains the ozone layer.

Step 1: Structure of Earth's atmosphere

The atmosphere is divided into layers based on temperature gradients:

Step 2: Location of the ozone layer

The ozone layer is concentrated in the stratosphere, approximately between 15 and 35 km above Earth's surface. Ozone (O₃) in this layer absorbs most of the Sun's harmful ultraviolet (UV-B and UV-C) radiation, preventing it from reaching Earth's surface.

Step 3: Significance

Depletion of the stratospheric ozone layer — caused primarily by chlorofluorocarbons (CFCs) — leads to increased UV radiation reaching Earth, which can cause skin cancer, cataracts, and damage to ecosystems.

Answer:

The ozone layer is found in the stratosphere.

Quick Tip:

Do not confuse stratospheric ozone (beneficial — shields UV) with tropospheric ozone (harmful — a pollutant and component of smog at ground level).