Physics: Mechanics: UPSC Previous Year Questions (Science and Technology)
3 previous year UPSC Prelims questions on Physics: Mechanics (Science and Technology). Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 1–3 of 3 questions
UPSC 2003Science and Technology · Physics: Mechanics
Q1. Assertion (A): The weight of a body decreases with the increase of altitude on earth. Reason (R): The earth is not a perfect sphere. Codes:
Explanation
Assertion (A) is true: Weight is the force of gravity acting on an object, and gravity weakens as the distance from the Earth>s center increases. Since altitude represents a greater distance from the Earth>s center, the force of gravity and thus the weight of the body diminish. Reason (R) is true: The Earth is not a perfect sphere, being slightly flattened at the poles and bulging at the equator, this fact does not primarily explain the decrease in weight with altitude. The primary reason lies in the inverse square law of gravity, which states that the force of gravity between two objects decreases proportionally to the square of the distance between them. Hence, Reason (R) does not correctly explain the Assertion (A).
UPSC 2003Science and Technology · Physics: Mechanics
Q2. Consider the following statements: A 4-wheel vehicle moving in a sharp circular path at high speed will: 1. Overturn about its outer wheels 2. Overturn about its inner wheels 3. Skid outwards 4. Skid inwards Which of these statements are correct?
Explanation
Statement 1 is correct: When a vehicle takes a sharp turn at high speed, the centrifugal force may push the vehicle outwards. This can cause the vehicle to tilt outwards and potentially overturn about its outer wheels.
Statement 2 is incorrect: This is less likely to happen. The centrifugal force pushes the vehicle outwards, not inwards.
Statement 3 is correct: If the friction between the tires and the road is insufficient to provide the necessary centripetal force, the vehicle may skid outwards, away from the center of the turn.
Statement 4 is incorrect: Skidding typically occurs outwards, not inwards, due to the centrifugal force.
UPSC 2003Science and Technology · Physics: Mechanics
Q3. An oil tanker partially filled with oil moves forward on a level road with uniform acceleration. The free surface of oil then:
Explanation
When the oil tanker accelerates forward, the oil inside experiences an inertial force (pseudo force) acting in the opposite direction to the acceleration. This causes the free surface of the oil to tilt. 1. The rear end of the tanker has larger depth because the inertial force pushes the oil backward.
2. The front end has smaller depth as the oil moves away from it. Thus, The free surface of the oil becomes inclined, with the rear end having a larger depth
Answer key for these questions
Q
UPSC year
Correct answer
1
2003
(b) Both A and R are true but R is not a correct explanation of A
2
2003
(a) 1 and 3
3
2003
(c) is inclined to the horizontal with larger depth at the rear end
Frequently asked questions
How many previous year UPSC questions are there on Physics: Mechanics?
This page covers 3 previous year UPSC Prelims GS Paper-I questions on Physics: Mechanics (Science and Technology), asked from 1997 to 2004. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Physics: Mechanics?
Questions on Physics: Mechanics (Science and Technology) are available for 7 years, from 1997 to 2004. Use the Year filter to practise a single paper.
