Physics
Class 9
Lakhmir Singh
1
Chapter 1: Motion
117 questions
2
Chapter 2: Force and Laws of Motion
114 questions
3
Chapter 3: Gravitation
157 questions
4
Chapter 4: Work and Energy
128 questions
Q1
Question 65:
Water stored in a dam possesses :
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy
Q2
Question 67:
Each of the following statement describes a force acting. Which force is causing work to be done?
(a) the weight of a book at rest on a table
(b) the pull of a moving railway engine on its coaches
(b) the tension in an elastic band wrapped around a parcel
(d) the push of a person's feet when standing on the floor
(a) the weight of a book at rest on a table
(b) the pull of a moving railway engine on its coaches
(b) the tension in an elastic band wrapped around a parcel
(d) the push of a person's feet when standing on the floor
Q3
Question 69:
Which of the following does not posses the ability to do work not because of motion?
(a) a sparrow flying in the sky
(b) a sparrow moving slowly on the ground
(c) a sparrow in the nest on a tree
(d) a squirrel going up a tree
View all question(a) a sparrow flying in the sky
(b) a sparrow moving slowly on the ground
(c) a sparrow in the nest on a tree
(d) a squirrel going up a tree
5
Chapter 5: Sound
162 questions
Question
Question 67:
Each of the following statement describes a force acting. Which force is causing work to be done?
(a) the weight of a book at rest on a table
(b) the pull of a moving railway engine on its coaches
(b) the tension in an elastic band wrapped around a parcel
(d) the push of a person's feet when standing on the floor
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Text solution
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Answer:
We will justify all statements one by one as:
(a) The weight of a book at rest on a table cannot do any work as the book is at rest. So, the work done by this force is zero.
(b) The pulling force applied by the railway engine on its coaches is doing work, as the force applied by the engine results in the motion of the coaches.
(c) The tension force in an elastic band wrapped around a parcel cannot do any work, as there is no motion of the parcel because of the tension force of the rubber band.
(d) The push of a person’s feet on a floor when he is standing cannot do any work because there is no motion involved due to the applied force.
Therefore, the answer is -
(b) The pull of a moving railway engine on its coaches.
(a) The weight of a book at rest on a table cannot do any work as the book is at rest. So, the work done by this force is zero.
(b) The pulling force applied by the railway engine on its coaches is doing work, as the force applied by the engine results in the motion of the coaches.
(c) The tension force in an elastic band wrapped around a parcel cannot do any work, as there is no motion of the parcel because of the tension force of the rubber band.
(d) The push of a person’s feet on a floor when he is standing cannot do any work because there is no motion involved due to the applied force.
Therefore, the answer is -
(b) The pull of a moving railway engine on its coaches.
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Practice more questions from Physics (Lakhmir Singh)
Q1
Question 65:
Water stored in a dam possesses :
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy
Q2
Question 67:
Each of the following statement describes a force acting. Which force is causing work to be done?
(a) the weight of a book at rest on a table
(b) the pull of a moving railway engine on its coaches
(b) the tension in an elastic band wrapped around a parcel
(d) the push of a person's feet when standing on the floor
(a) the weight of a book at rest on a table
(b) the pull of a moving railway engine on its coaches
(b) the tension in an elastic band wrapped around a parcel
(d) the push of a person's feet when standing on the floor
Q3
Question 69:
Which of the following does not posses the ability to do work not because of motion?
(a) a sparrow flying in the sky
(b) a sparrow moving slowly on the ground
(c) a sparrow in the nest on a tree
(d) a squirrel going up a tree
View all(a) a sparrow flying in the sky
(b) a sparrow moving slowly on the ground
(c) a sparrow in the nest on a tree
(d) a squirrel going up a tree
Practice questions from Physics (Lakhmir Singh)
Question 1
Views: 5,201
(a) A stone kept on roof-top
(b) A running car
(c) Water stored in the reservoir of a dam
(d) A compressed spring
(e) A stretched rubber band
Question 2
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(a) by the stretched rubber strings of a catapult?
(b) by the piece of stone which is thrown away on releasing the stretched rubber strings of catapult?
Figure
Question 4
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(a) increases
(b) decreases
(c) remains constant
(d) first increases and then decreases
Practice more questions from Work and Energy
Question 2
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(i) Electrical energy into sound energy.
(ii) Heat energy into kinetic energy (or mechanical energy).
(iii) Chemical energy into kinetic energy (or mechanical energy).
(iv) Chemical energy into heat energy.
(v) light energy into heat energy.
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| Question Text | Question 67:
Each of the following statement describes a force acting. Which force is causing work to be done? (a) the weight of a book at rest on a table (b) the pull of a moving railway engine on its coaches (b) the tension in an elastic band wrapped around a parcel (d) the push of a person's feet when standing on the floor |
| Topic | Work and Energy |
| Subject | Science |
| Class | Class 9 |
| Answer Type | Text solution:1 |
| Upvotes | 72 |
