Science & Technology

1 Q. Dialysis is used for a patient suffering from

(a) Kidney trouble

(b) Liver trouble

(c) Lung trouble

(d) Bronchitis

Correct Answer: (b) Methane

Explanation:
Biogas (commonly called Gobar gas) is produced by the anaerobic decomposition of animal dung and organic waste in a Biogas Plant.

The main component of biogas is Methane, which is responsible for its fuel value.

Typical Composition of Gobar Gas (Biogas):

• Methane (CH₄) → ~55–65%

• Carbon Dioxide → ~30–40%

• Small amounts of hydrogen, nitrogen, and hydrogen sulphide.

4 Q. Decrease in white blood cells results in
(a) Decrease in Antibodies
(b) Increase in Antigens
(c) Increase in Antibodies
(d) No change

Correct Answer: (a) Decrease in Antibodies

Explanation:
White blood cells (WBCs), especially Lymphocytes, play a major role in the body’s immune system. Some lymphocytes (B-cells) produce Antibodies to fight infections.

If the number of White Blood Cells decreases, the body produces fewer antibodies, which weakens the immune response.

Q5. Pulse reading is done by doctors to find out
(a) Temperature
(b) Heart beat
(c) Blood pressure
(d) Respiration rate

Correct Answer: (b) Heart beat

Explanation:
Doctors check the Pulse to measure the Heart Rate.

Each time the Heart beats, it pushes blood through the arteries, creating a pulse that can be felt at places like the wrist or neck.

Q9. After how many days rash appears on the body after the attack of Measles ?
(a) One day
(b) Four days
(c) Six days
(d) One week

Correct Answer: (b) Four days

Explanation:
Measles usually starts with fever, cough, and cold. Skin rash generally appears about 3–4 days after the fever begins.

Q10. The Vitamin responsible for anti-sterile activity is
(a) Vitamin A
(b) Vitamin B
(c) Vitamin C
(d) Vitamin D

Correct Answer: (d) Vitamin D

Explanation:
Vitamin D was historically called the anti-sterility vitamin because deficiency may affect reproductive functions in animals.

Q11. The water in an open pond remains cool even in hot summer because
(a) Of continuous evaporation of water
(b) Water radiates heat more rapidly than the atmosphere
(c) Water absorbs heat less rapidly than the atmosphere
(d) Water absorbs heat more rapidly than the atmosphere

Correct Answer: (a) Of continuous evaporation of water

Explanation:
Due to Evaporation, water molecules escape into the air and take heat energy with them, which cools the remaining water.

Q12. You are travelling in a car and a thunder storm suddenly takes place. What will be your first step ?
(a) Stop the car, get out of it and lie flat in the field
(b) Stand below a tree
(c) Go to a nearby wood pole and stick to it
(d) Lie flat in the car

Correct Answer: (d) Lie flat in the car

Explanation:
During a Thunderstorm, a car acts like a protective metal shell (Faraday cage effect), making it safer to remain inside the car rather than standing outside, under trees, or near poles.

Q13. If a large number of people are enclosed in a room, then
(a) Oxygen decreases and carbon dioxide increases
(b) Oxygen increases and carbon dioxide decrease
(c) Both oxygen and carbon dioxide decrease
(d) Both oxygen and carbon dioxide increase

Correct Answer: (a) Oxygen decreases and carbon dioxide increases

Explanation:
Humans inhale oxygen and exhale Carbon Dioxide during Respiration.
So in a closed room with many people, oxygen level decreases while carbon dioxide level increases.

Q14. It is not advisable to sleep under a tree at night because of the
(a) Release of oxygen in lesser amount
(b) Release of oxygen in larger amount
(c) Release of carbon monoxide
(d) Release of carbon dioxide

Correct Answer: (d) Release of carbon dioxide

Explanation:
At night, plants perform Respiration instead of Photosynthesis.
So they consume oxygen and release carbon dioxide, which can make the air less suitable for breathing.

Q15. Higher plants take up Nitrogen as
(a) Nitrites only
(b) Nitrates only
(c) Nitrates and ammonia
(d) Urea

Correct Answer: (c) Nitrates and ammonia

Explanation:
Plants cannot directly use atmospheric nitrogen. They absorb nitrogen from soil mainly as Nitrate and Ammonia through their roots.

Q16. Green plants in the sea are useful for the respiration of fish because
(a) They give out oxygen
(b) They give out carbon dioxide
(c) The give out oxygen and carbon dioxide simultaneously
(d) They take oxygen and give out carbon dioxide

Correct Answer: (a) They give out oxygen

Explanation:
Aquatic plants carry out Photosynthesis, releasing Oxygen into water, which fish use for breathing.

Q17. Stripes on the back of the animals are the indication of
(a) Mating habit
(b) Food habit
(c) Cave dwelling
(d) Matching of skin colour with surroundings

Correct Answer: (d) Matching of skin colour with surroundings

Explanation:
This is an example of Camouflage, which helps animals avoid predators or hunt prey by matching their environment.

Q18. Which of the following is not immunised by ‘Triple Antigen’ ?
(a) Typhoid
(b) Whooping cough
(c) Tetanus
(d) Diphtheria

Correct Answer: (a) Typhoid

Explanation:
The DPT Vaccine (Triple Antigen) protects against:

• Diphtheria

• Whooping Cough

• Tetanus

It does not protect against Typhoid.

Q19. Milk fever in cows occurs due to the lack of
(a) Phosphates
(b) Calcium
(c) Iron
(d) iodine

Correct Answer: (b) Calcium

Explanation:
Milk Fever occurs when there is a sudden drop in Calcium levels in the blood of cows after giving birth.

Q20. After hatching by the hen, the young chicks come out of eggs within
(a) One week
(b) Two weeks
(c) Three weeks
(d) Four weeks

Correct Answer: (c) Three weeks

Explanation:
The incubation period of Chicken eggs is about 21 days (3 weeks) before chicks hatch.