Physics Questions for CDS & CAPF: 10th September

Dear Aspirants, Physics is an important subject in various exams like NDA, CDS, AFCAT, CAPF and other Police Exams. Here at Defence Adda we provide you with the quizzes based on the syllabus and pattern of these exams. The questions asked are of 10+2 level and preparing with a wide variety of questions will only help you ace in these exams. Here is a quiz based on the latest syllabus of these exams and covering various topics like Quantum Mechanics, Light, Thermodynamics,
Magnetism etc to help you prepare with a wide variety of questions.
Q1. Which one of the following Indian scientists was elected as a fellow of the Royal Society of London for his contribution in the field of Plant Physiology and Physics?
(a) Ashutosh Mukherjee
(b) Jagdish Chandra Bose
(c) Prafulla Chandra Ray
(d) P C Mahalanodis

Q2. Assertion (A): Steam is more harmful for human body than the boiling water in case of burn.
Reason (R) : Boiling water contains more heat than steam.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and  R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true

Q3. Why is it difficult to see through for?
(a) Rays of light suffer total internal reflection from the fog droplets
(b) Rays of light are scattered by the fog droplets
(c) Fog droplets absorb light
(d) The refractive index of fog is extremely high

Q4. The density of water varies with temperature which helps the aquatic animals to live in cold water. At what temperature is the density of water maximum?
(a) 1°C
(b) 2°C
(c) 3°C
(d) 4°C

Q5. Who gave the first evidence of the big-bang theory?
(a) Edwin Hubble
(b) Albert Einstein
(c) S Chandrasekhar
(d) Stephen Hawking

Q6. A ray of light is incident on a plane mirror at an angle 30° with the normal at the point of incidence. The ray will be deviated from its incidence direction by what angle?
(a) 30°
(b) 60°
(c) 120°
(d) None of these

Q7. What would be the best choice for window material to keep the outside heat away?
(a) Single-pane glass
(b) Double-pane glass without a gap in between
(c) Double-pane glass with water filled in between
(d) Double-pane glass with air in between

Q8. Bar is a unit of which one of the following?
(a) Force
(b) Energy
(c) Pressure
(d) Frequency

Q9. On which one of the following conservative laws, does a rocket work?
(a) Mass
(b) Energy
(c) Linear momentum
(d) Angular momentum

Q10. Assertion (A) : In a pressure cooker food is cooked above boiling point.
Reason (R) : Boiling point of water increases as the pressure increases.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true

SOLUTIONS
S1. Ans.(b)
Sol.
Jagdish Chandra Bose was elected as a fellow of the Royal Society of London for his contribution in the field of Plant Physiology and Physics.

S2. Ans.(c)
Sol.
Steam burns are more serious than burns from boiling water even though both are at 100°C because when steam condenses it give up very high heat energy i.e. additional 22.6 × 〖10〗^6 joule of heat (latent that of vapourisation) compared to boiling water.

S3. Ans.(b)
Sol.
The rays of light are scattered by the fog droplets due to which it become difficult to see through fog.

S4. Ans.(d)
Sol.
Density of water is maximum at 4°C.

S5. Ans.(a)
Sol.
Edwin Hubble gave the first evidence of the big-bang theory.

S7. Ans.(d)
Sol.
To keep the outside heat away, windows of double-pane glass with air in between is the best choice because air is the bad conductor of heat.

S8. Ans.(c)
Sol.
To keep the outside heat away, windows of double-pane glass with air in between is the best choice because air is the bad conductor of heat.

S9. Ans.(c)
Sol.
Rocket works on the principle of conservation of linear momentum.

S10. Ans.(a)
Sol.
In a pressure cooker while cooking pressure increases due to which boiling point of water also increases as P ∝ T.