NCERT  ·  Science  ·  Class IX  ·  Ch.9

Work and Energy
MCQ Master Series

Work · Kinetic Energy · Potential Energy · Conservation of Energy · Power

🔥 50 Questions
⏱ 30 min Suggested
📊 3 Tiers
🗂 5 Topics
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Question Intelligence

Quiz Analytics

A data-driven breakdown of all 50 questions by difficulty, exam origin and topic distribution.

📈 Distribution Overview

50
Total Questions
CBSE Board
25
State Board
16
Olympiad Level
9

🗂 Topic Coverage

Work Done
20%
Kinetic Energy
20%
Potential Energy
18%
Conservation of Energy
24%
Power & Commercial Energy
18%
25
CBSE Board
16
State Board
9
Olympiad Level
Conceptual Framework

Key Concept Highlights

6 foundational pillars that power every question in this quiz. Understand these, and the answers follow naturally.

🏋️
Work Done
W = Fs cosθ. Work is done only when force causes displacement. Positive work (force and displacement same direction), negative work (opposite), zero work (perpendicular). SI unit: joule (J).
🏎️
Kinetic Energy
Energy of a moving object. KE = ½mv². Depends on both mass and velocity (velocity has more influence: KE ∝ v²). Work-energy theorem: net work done = change in KE.
🏔️
Gravitational PE
Energy stored due to position in a gravitational field. PE = mgh. Depends on mass, height, and g. Reference level (h=0) is arbitrary but must be consistent.
⚡
Conservation of Energy
Energy can neither be created nor destroyed, only converted from one form to another. Total mechanical energy (KE + PE) is constant in the absence of friction. The fundamental law of nature.
💡
Power
Rate of doing work. P = W/t = Fv. SI unit: watt (W = J/s). 1 horsepower = 746 W. Commercial unit: kilowatt-hour (kWh). 1 kWh = 3.6 × 10⁶ J.
🔄
Energy Transformations
Pendulum: KE↔PE. Hydroelectric: PE→KE→electrical. Photosynthesis: light→chemical. Burning fuel: chemical→heat+light. Energy quality degrades (entropy) though quantity is conserved.
Pedagogical Value

Why MCQs Matter

Multiple-choice questions are not mere guessing games — they are the sharpest diagnostic tool available to a competitive exam aspirant.

~12%

of CBSE Class IX Science — energy conservation numericals are essential exam content

Quick Reference

Important Formula Capsules

6 must-memorise equations that surface repeatedly across CBSE and JEE papers.

Work Done
\[ W = Fs\cos\theta \]
Kinetic Energy
\[ KE = \dfrac{1}{2}mv^2 \]
Gravitational PE
\[ PE = mgh \]
Work–Energy Theorem
\[ W_{\text{net}} = \Delta KE = \tfrac{1}{2}mv^2 - \tfrac{1}{2}mu^2 \]
Power
\[ P = \dfrac{W}{t} = Fv \]
kWh to Joules
\[ 1\ \text{kWh} = 3.6 \times 10^6\ \text{J} \]
Learning Outcomes

What You Will Learn

By completing this quiz set you will have exercised all the following competencies.

01 Apply W = Fs cosθ and identify conditions when work done is zero
02 Derive the expression for kinetic energy using the work-energy theorem
03 Calculate gravitational PE and use it in energy conservation problems
04 Apply the law of conservation of energy to a falling body at various heights
05 Calculate power in watts and convert between watts, kilowatts, and horsepower
06 Convert units: joules, kilowatt-hours, and calories
Exam Preparation

Strategy & Preparation Tips

4 evidence-based strategies to maximise your score in CBSE Boards and JEE.

Step 01
Zero Work Checklist
Work = 0 when: (1) no displacement (wall push), (2) force perpendicular to displacement (gravity on horizontal motion), (3) no force. CBSE asks these as MCQs directly.
Step 02
Energy Conservation Template
At point A: KE₁ + PE₁ = At point B: KE₂ + PE₂. Write this before every problem. Most errors come from not setting h=0 at the lowest point first.
Step 03
Power = Fv Short Form
When a vehicle moves at constant velocity, P = Fv (where F = driving force). This shortcut halves the steps for power numericals involving speed and force.
Step 04
Commercial Unit MCQs
1 unit of electricity = 1 kWh. Bill = power(kW) × time(h) × rate(₹/unit). CBSE gives electricity bill numericals every year — practise 3 examples.

Ready to Test Your Mastery?

50 questions  ·  Elapsed timer  ·  Instant scored results

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🎯 Knowledge Check

Science — Work And Energy

50 Questions Class 9 MCQs
1
Work is said to be done when
2
SI unit of work is
3
No work is done if
4
The work done by the force of gravity on a falling object is
5
The energy possessed by a body due to its motion is called
6
Kinetic energy of a body depends on its
7
If the velocity of a body is doubled, its kinetic energy becomes
8
Potential energy depends on
9
Work done is zero when the angle between force and displacement is
10
Power is defined as
11
SI unit of power is
12
1 kilowatt =
13
The work done on an object is positive when
14
A freely falling body has
15
Unit of energy is same as that of
16
Work done in lifting an object depends on
17
When a spring is stretched, the energy stored in it is
18
Which of the following is not a form of mechanical energy?
19
1 horsepower =
20
The energy of a body due to its position or configuration is
21
The work done by centripetal force is
22
When a man walks on a level road, the work done against gravity is
23
If a force of 10 N moves an object by 2 m in its direction, work done is
24
When velocity of a body becomes zero, its kinetic energy is
25
Work done = 0 if displacement is
26
The commercial unit of energy is
27
1 kilowatt-hour =
28
The rate of doing work is called
29
Mechanical energy of a moving body is
30
Work done in moving an object on a frictionless surface is
31
When force and displacement are in opposite direction, work done is
32
Work done per unit time is
33
Energy can neither be created nor destroyed. This statement is known as
34
A body of mass 1 kg moving with velocity 2 m/s has kinetic energy of
35
The faster a body moves, the ___________ its kinetic energy.
36
Work done on a body by gravity during free fall depends on
37
The energy transformation in an electric fan is
38
A car engine converts
39
Potential energy of an object is due to its
40
If 100 J of work is done in 2 seconds, power is
41
The work done by the Earth’s gravity on a satellite moving around it is
42
Which of these has maximum kinetic energy?
43
Energy possessed by a stretched rubber band is
44
A freely falling object just before touching the ground has
45
When an object is thrown upward, its kinetic energy is converted into
46
Which quantity remains constant for a freely falling object (neglecting air resistance)?
47
If a man lifts a 20 kg bag through 2 m, work done = ? \((g = 10 m/s^2)\)
48
The work done against friction is converted into
49
An electric bulb converts
50
Which of the following has both potential and kinetic energy?
📚
ACADEMIA AETERNUM तमसो मा ज्योतिर्गमय · Est. 2025
Sharing this chapter
Work And Energy | Science Class 9 | Academia Aeternum
Work And Energy | Science Class 9 | Academia Aeternum — Complete Notes & Solutions · academia-aeternum.com
The chapter “Work and Energy” introduces students to two of the most fundamental concepts in Physics. It explains how work is done when a force causes displacement and connects it with the concept of energy — the ability to do work. Students learn about different forms of energy such as kinetic and potential energy, their interconversion, and the law of conservation of energy. The chapter also explores the concepts of power, units of work and energy, and practical energy transformations in…
🎓 Class 9 📐 Science 📖 NCERT ✅ Free Access 🏆 CBSE · JEE
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💡
Exam tip: Sharing chapter notes with your study group creates a reinforcement loop. Teaching a concept is the fastest path to mastering it.

Frequently Asked Questions

Water at the top of a dam possesses potential energy.

Energy can neither be created nor destroyed; it only changes form. The total energy in a closed system remains constant.

In a pendulum, energy continuously converts between kinetic and potential, but total energy stays the same.

Power is the rate of doing work or transferring energy per unit time.

Power (P) = Work done (W) / Time taken (t); unit: watt (W)

The SI unit of power is watt (W).

Work is energy transferred by force; energy is the ability to do work; power is the rate of doing work.

One joule is the work done when a force of one newton displaces an object by one meter in the direction of force.

Elastic potential energy.

It is transformed into another form (e.g., heat, sound).

Kinetic energy.

Wattmeter.

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    Work and Energy — Learning Resources

    📄 Detailed Notes
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    WORK AND ENERGY-Exercise
    📚
    ACADEMIA AETERNUM तमसो मा ज्योतिर्गमय · Est. 2025
    Sharing this chapter
    Work And Energy | Science Class 9 | Academia Aeternum
    Work And Energy | Science Class 9 | Academia Aeternum — Complete Notes & Solutions · academia-aeternum.com
    The chapter “Work and Energy” introduces students to two of the most fundamental concepts in Physics. It explains how work is done when a force causes displacement and connects it with the concept of energy — the ability to do work. Students learn about different forms of energy such as kinetic and potential energy, their interconversion, and the law of conservation of energy. The chapter also explores the concepts of power, units of work and energy, and practical energy transformations in…
    🎓 Class 9 📐 Science 📖 NCERT ✅ Free Access 🏆 CBSE · JEE
    Share on
    WhatsApp
    Telegram
    X / Twitter
    Facebook
    Instagram
    Threads
    Pinterest
    LinkedIn
    Quora
    Discord
    Reddit
    Email
    academia-aeternum.com/class-9/science/work-and-energy/mcqs/ Copy link
    💡
    Exam tip: Sharing chapter notes with your study group creates a reinforcement loop. Teaching a concept is the fastest path to mastering it.

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