PhysicsICSE Class 10 · Chapter 4

Different Types of Energy ICSE Class 10: Potential and Kinetic Energy and Energy Conversions

Updated 14 October 2026 · Fact-checked

Energy exists in many forms: mechanical, chemical, heat, electrical, nuclear, sound and light. Mechanical energy is potential energy U = mgh (due to position) plus kinetic energy K = ½mv² (due to motion). In ICSE Class 10 you derive both formulas, solve translational numericals and state energy conversions in devices.

What Different Types of Energy is about

Energy is the capacity to do work, and it appears in many forms that can change from one to another. This chapter is about the forms of energy, especially mechanical energy, and about naming the conversion that happens in everyday devices.

The CISCE 2027 syllabus covers: different types of energy (chemical, mechanical, heat, electrical, nuclear, sound and light); potential energy $U = m g h$ with derivation and examples; kinetic energy $K = \frac{1}{2} m v^{2}$ with derivation; forms of kinetic energy (translational, rotational, vibrational), with simple examples only; numerical problems on $K$ and $U$ for translational motion only; and qualitative discussion of the other forms and of conversions between them.

The CISCE examiners' comments for 2024 and 2025 show that energy-conversion MCQs are lost by rote answers: a cycle bell taken as 'electrical to sound' or 'potential to sound', and a burning candle as 'heat to chemical and light'. Think about the energy before and after the process.

Weightage: CISCE publishes no chapter or unit weightage for ICSE Physics. Different Types of Energy is in the 1. Force, Work, Power and Energy (iv) part of the 2027 syllabus and can be asked in both Section A and Section B of the 80-mark paper.Source: CISCE ICSE Physics (Science Paper 1) syllabus, examination year 2027

Key concepts

Forms of energy

Mechanical: potential (position or shape) and kinetic (motion).
Chemical: stored in the bonds of fuels, food and cells; released in reactions.
Heat (thermal): energy of random motion of molecules.
Electrical: energy of moving charges; carried by current.
Nuclear: stored in the nucleus; released in fission and fusion.
Sound: carried by vibrations through a medium.
Light: radiant energy that travels even through a vacuum.

All are measured in joules.

Worked example

Name the main form of energy stored in (a) a dry cell, (b) a stretched rubber band, (c) uranium fuel.

Try it first, then show the solutionSolution

(a) Chemical energy.
(b) Elastic potential energy (mechanical).
(c) Nuclear energy.

Answer: (a) chemical (b) potential (c) nuclear

Potential energy and U = mgh

Potential energy is the energy a body has because of its position or configuration (shape). Examples: water stored in a dam, a wound watch spring, a stretched bow, a raised hammer.

Derivation of gravitational PE: to lift a body of mass $m$ slowly through height $h$ , an upward force equal to its weight $m g$ acts through distance $h$ . Work done $= m g \times h$ . This work is stored in the body, so
$U = m g h$ .

PE is measured from a chosen reference level (usually the ground); it changes if the reference level changes.

Worked example

Find the PE of a 2 kg body 5 m above the ground. What is its PE if raised a further 5 m? ( $g = 10$ m s⁻²)

Try it first, then show the solutionSolution

$U = 2 \times 10 \times 5 = 100$ J.
At 10 m: $U = 2 \times 10 \times 10 = 200$ J (doubles with height).

Answer: 100 J; 200 J

Kinetic energy and K = ½mv²

Kinetic energy is the energy a body has because of its motion.

Derivation: a constant force $F$ acts on a body of mass $m$ at rest and gives it speed $v$ over distance $s$ . From $v^{2} = u^{2} + 2 a s$ with $u = 0$ : $s = \frac{v ^{2}}{2 a}$ . Work done $W = F s = ma \times \frac{v ^{2}}{2 a} = \frac{1}{2} m v^{2}$ . This work appears as kinetic energy:
$K = \frac{1}{2} m v^{2}$ .

KE is proportional to mass and to the square of speed: doubling the speed makes KE four times as large.

Worked example

Find the kinetic energy of a 0.5 kg ball moving at 4 m/s.

Try it first, then show the solutionSolution

$K = \frac{1}{2} \times 0.5 \times 4^{2}$
$= 4$ J.

Answer: 4 J

Forms of kinetic energy

Translational: the whole body moves from one place to another (a moving car, a falling stone).
Rotational: the body spins about an axis (a ceiling fan, a spinning top, the Earth on its axis).
Vibrational: the body moves to and fro about a mean position (a plucked guitar string, the prongs of a tuning fork, atoms in a solid).

A rolling ball has both translational and rotational KE. Numerical problems are only on translational KE.

Worked example

Name the form of KE in (a) a moving train, (b) a spinning top, (c) the vibrating skin of a drum.

Try it first, then show the solutionSolution

(a) Translational.
(b) Rotational.
(c) Vibrational.

Answer: (a) translational (b) rotational (c) vibrational

Energy conversions in devices and processes

Name the energy at the start and at the end:

burning candle or fuel: chemical → heat + light;
electric bulb: electrical → light + heat;
electric heater or iron: electrical → heat;
loudspeaker: electrical → sound; microphone: sound → electrical;
electric motor: electrical → mechanical; dynamo or generator: mechanical → electrical;
cell or battery (in use): chemical → electrical;
solar cell: light → electrical; photosynthesis: light → chemical;
ringing a bicycle bell by hand: kinetic (mechanical) → sound;
hydroelectric plant: potential → kinetic → electrical.

Worked example

State the energy change when (a) a cycle bell is rung, (b) a candle burns.

Try it first, then show the solutionSolution

(a) The moving lever and striker have kinetic energy, which makes the bell vibrate: kinetic → sound.
(b) Wax (fuel) releases its chemical energy on burning: chemical → heat + light.

Answer: (a) kinetic → sound (b) chemical → heat and light

Using the formulas in numericals

Use SI units: mass in kg, speed in m/s, height in m, energy in J. Convert km/h to m/s by multiplying by $\frac{5}{18}$ .
The work done to change KE: $W = K_{final} - K_{initial}$ .
The work done against gravity to change height: $W = m g (h_{2} - h_{1})$ .
From $K = \frac{1}{2} m v^{2}$ : $v = \frac{2 K}{m}$ .

Worked example

A car of mass 1000 kg speeds up from 36 km/h to 72 km/h. Find the increase in its kinetic energy.

Try it first, then show the solutionSolution

36 km/h $= 10$ m/s; 72 km/h $= 20$ m/s.
$K_{1} = \frac{1}{2} \times 1000 \times 100 = 5 \times 1 0^{4}$ J; $K_{2} = \frac{1}{2} \times 1000 \times 400 = 2 \times 1 0^{5}$ J.
Increase $= 1.5 \times 1 0^{5}$ J (this is the net work done on the car).

Answer: 1.5 × 10⁵ J

Physics in real life: Different Types of Energy

Each concept, met in an everyday situation. Read the situation, try the problem, then check the solution. The one-line hook is what to remember.

Energy chain in a hydroelectric plant

Suppose 1000 kg of water stored 80 m above the turbines falls through the pipes of a dam.

Find its PE at the top and the electrical energy produced if 75% is converted. ( $g = 10$ m s⁻²)

Try it first, then show the solutionSolution

$U = 1000 \times 10 \times 80 = 8 \times 1 0^{5}$ J.
Chain: potential → kinetic → rotational KE of turbine → electrical.
Electrical energy $= 0.75 \times 8 \times 1 0^{5} = 6 \times 1 0^{5}$ J.

Answer: 8 × 10⁵ J; 6 × 10⁵ J

Memory hook: Height becomes speed becomes spin becomes current.

Kinetic energy depends on v²

Imagine a 0.16 kg cricket ball bowled at 30 m/s, and then a slower ball at 15 m/s.

Compare their kinetic energies.

Try it first, then show the solutionSolution

Fast ball: $K = \frac{1}{2} \times 0.16 \times 900 = 72$ J.
Slow ball: $K = \frac{1}{2} \times 0.16 \times 225 = 18$ J.
Half the speed gives a quarter of the KE.

Answer: 72 J and 18 J (4 : 1)

Memory hook: Speed squared.

Conversions at home

Suppose in one evening you switch on a bulb, play music on a speaker and boil water in an electric kettle.

State the main energy conversion in each device.

Try it first, then show the solutionSolution

Bulb: electrical → light (and heat).
Speaker: electrical → sound.
Kettle: electrical → heat.

Answer: Electrical to light, sound and heat

Memory hook: Electrical energy is the great converter at home.

Topics in this chapter

Different Types of Energy formula sheet

Gravitational potential energy: $U = m g h$; h measured from the reference level.
Kinetic energy: $K = \frac{1}{2} m v^{2}$; v in m/s.
Speed from kinetic energy: $v = \frac{2 K}{m}$; Rearranged.
Work–energy: $W = K_{2} - K_{1}$; Net work changes the kinetic energy.
Mechanical energy: $E = U + K$; Sum of potential and kinetic energy.
Speed conversion: $1 km/h = \frac{5}{18} m/s$; Convert before using K = ½mv².

How the board asks Different Types of Energy

The question patterns to expect, and the method that works for each.

Question type	How it is asked	Method
MCQ: energy conversion	Section A, Question 1: the energy change in a bell, candle, solar cell, microphone, etc.	Name the form before and after; do not rely on a remembered phrase.
Derivations (3 marks)	Derive U = mgh or K = ½mv².	Work done = force × distance, then identify it as stored energy.
Numericals on U and K	PE at a height, KE at a speed, change in KE, speed from KE.	SI units; square the speed; subtract for changes.
Forms of kinetic energy	Identify translational, rotational or vibrational KE in examples.	Moves along, spins, or vibrates.
Ratios	Effect of doubling speed or mass; equal KE with different masses.	K ∝ m and K ∝ v².

Tricks to remember Different Types of Energy

Short memory aids. Say each one aloud once, then use it on a question the same day.

Position or motion
Potential = Position (or shape); Kinetic = Kinetics (motion).
Use it when: Defining the two.
Speed is squared
Double the speed, four times the KE; triple it, nine times.
Use it when: Ratio questions.
Before → after
For any conversion, ask: what was stored before, and what came out after?
Use it when: Conversion MCQs.
Trans, rot, vib
Travels, turns, trembles: translational, rotational, vibrational.
Use it when: Forms of KE.

Different Types of Energy: board-level solved questions

Ordered from board level to HOTS. Cover the solution, write your own, then compare step by step.

Example 1: Solar cell · 1 mark · MCQBoard level

In a solar cell, the energy conversion is:
(a) chemical to electrical
(b) light to electrical
(c) electrical to light
(d) heat to electrical

Try it first, then show the solutionSolution

Sunlight falls on the cell and an electric current is produced.

Answer: (b)

Example 2: Doubling speed · 1 mark · Assertion-reasonBoard level

Assertion (A): If the speed of a body is doubled, its kinetic energy becomes four times.
Reason (R): The kinetic energy of a body is $\frac{1}{2} m v^{2}$ .
(a) (A) is true and (R) is false.
(b) (A) is false and (R) is true.
(c) Both (A) and (R) are true, and (R) is the correct explanation for (A).
(d) Both (A) and (R) are true, but (R) is not the correct explanation for (A).

Try it first, then show the solutionSolution

$K \propto v^{2}$ , so $(2 v)^{2} = 4 v^{2}$ .

Answer: (c)

Example 3: Potential energy and work against gravity · 2 marks · Short answerBoard level

A ball of mass 0.5 kg is thrown up and rises to a height of 12 m above the ground. Find (a) its potential energy at the highest point, (b) the work done against gravity while it rises from 4 m to 12 m. ( $g = 10$ m s⁻²)

Try it first, then show the solutionSolution

(a) $U = m g h = 0.5 \times 10 \times 12 = 60$ J.
(b) $W = m g (h_{2} - h_{1}) = 0.5 \times 10 \times (12 - 4) = 40$ J.

Answer: (a) 60 J (b) 40 J

Example 4: Derive K = ½mv² · 3 marks · Short answerHarder board level

A body of mass $m$ at rest is acted on by a constant force $F$ and acquires a speed $v$ . Derive an expression for its kinetic energy.

Try it first, then show the solutionSolution

Acceleration $a = \frac{F}{m}$ . With $u = 0$ : $v^{2} = 2 a s$ , so $s = \frac{v ^{2}}{2 a}$ .
Work done $W = F \times s = ma \times \frac{v ^{2}}{2 a}$ .
$W = \frac{1}{2} m v^{2}$ ; this work is stored as kinetic energy, so $K = \frac{1}{2} m v^{2}$ .

Answer: K = ½mv²

Example 5: Speeding up a car · 3 marks · Short answerHarder board level

A car of mass 1000 kg increases its speed from 36 km/h to 72 km/h. Find (a) the initial and final KE, (b) the work done on the car.

Try it first, then show the solutionSolution

Speeds: 10 m/s and 20 m/s.
(a) $K_{1} = 5 \times 1 0^{4}$ J; $K_{2} = 2 \times 1 0^{5}$ J.
(b) $W = K_{2} - K_{1} = 1.5 \times 1 0^{5}$ J.

Answer: (a) 5 × 10⁴ J, 2 × 10⁵ J (b) 1.5 × 10⁵ J

Example 6: Forms of kinetic energy · 2 marks · Long answerBoard level

Name the form of kinetic energy in: (a) a rotating ceiling fan, (b) a vibrating guitar string, (c) a moving bus, (d) a ball rolling on the ground.

Try it first, then show the solutionSolution

(a) Rotational. (b) Vibrational.
(c) Translational. (d) Translational and rotational.

Answer: (a) rotational (b) vibrational (c) translational (d) both translational and rotational

Example 7: Reference level for PE · 3 marks · Long answerHarder board level

A book of mass 5 kg rests on a shelf 2 m above the floor of a room that is 10 m above the ground. Find its PE relative to (a) the floor, (b) the ground. (c) What does this show? ( $g = 10$ m s⁻²)

Try it first, then show the solutionSolution

(a) $5 \times 10 \times 2 = 100$ J.
(b) $5 \times 10 \times 12 = 600$ J.
(c) Potential energy depends on the chosen reference level; only changes in PE are physically fixed.

Answer: (a) 100 J (b) 600 J

Example 8: Bullet versus athlete · 4 marks · Long answerHOTS / competency

A 50 g bullet moves at 400 m/s and a 50 kg athlete runs at 8 m/s. (a) Find the KE of each. (b) Which has more KE, and by what ratio? (c) How fast would the athlete need to run to have the same KE as the bullet?

Try it first, then show the solutionSolution

(a) Bullet: $\frac{1}{2} \times 0.05 \times 40 0^{2} = 4000$ J. Athlete: $\frac{1}{2} \times 50 \times 64 = 1600$ J.
(b) The bullet: $4000 : 1600 = 5 : 2$ .
(c) $v = \frac{2 \times 4000}{50} = 160 \approx 12.65$ m/s.
The bullet's tiny mass is outweighed by its very large speed, because KE depends on $v^{2}$ .

Answer: (a) 4000 J, 1600 J (b) bullet, 5 : 2 (c) about 12.65 m/s

Case-study practice (Section B style)

Read the situation, then answer every part. In the board paper this is a 10-mark question split into 3 + 3 + 4 marks.

A hydroelectric power station

Imagine water stored behind a dam falls through 80 m to turbines that drive generators. ( $g = 10$ m s⁻²)

(i) · 3 marks
Write the chain of energy conversions from the stored water to electricity.
Answer
Answer: PE → KE → rotational KE → electrical
Stored water has gravitational PE; as it falls this becomes KE; the water turns the turbine (rotational KE); the generator converts this mechanical energy into electrical energy.
(ii) · 3 marks
Find the PE of 1000 kg of water at the top.
Answer
Answer: 8 × 10⁵ J
$U = m g h = 1000 \times 10 \times 80 = 8 \times 1 0^{5}$ J.
(iii) · 4 marks
If 75% of this becomes electrical energy, find it in joules and in kW h (to 3 decimal places).
Answer
Answer: 6 × 10⁵ J ≈ 0.167 kW h
$0.75 \times 8 \times 1 0^{5} = 6 \times 1 0^{5}$ J. $\frac{6 \times 1 0 ^{5}}{3.6 \times 1 0 ^{6}} \approx 0.167$ kW h.

Energy in a cricket match

Suppose a fast bowler delivers a 0.16 kg ball at 30 m/s; a spinner bowls the same ball at 15 m/s while making it spin quickly.

(i) · 3 marks
Find the translational KE of the ball from the fast bowler.
Answer
Answer: 72 J
$K = \frac{1}{2} \times 0.16 \times 3 0^{2} = 72$ J.
(ii) · 3 marks
Find the translational KE of the spinner's delivery and the ratio of the two.
Answer
Answer: 18 J; 4 : 1
$\frac{1}{2} \times 0.16 \times 1 5^{2} = 18$ J. $72 : 18 = 4 : 1$ , because KE $\propto v^{2}$ .
(iii) · 4 marks
Name the other form of KE the spinner's ball has, and the conversions when the ball hits the stumps and stops.
Answer
Answer: Rotational; KE → sound, heat and the stumps' KE
It also has rotational KE because it spins. On hitting the stumps, its kinetic energy changes into sound (the click), heat, a little elastic PE as the ball deforms, and kinetic energy of the flying bails and stumps.

Where the marks are

How a typical answer is split into step marks. Show every step: a right final answer alone rarely earns full marks.

Find the kinetic energy of a 3 kg body moving at 4 m/s. (2 marks)

Step	Marks
$K = \frac{1}{2} \times 3 \times 4^{2}$	1
$= 24$ J	1

Derive an expression for the gravitational potential energy of a body of mass $m$ at height $h$ . (3 marks)

Step	Marks
Force needed to lift it slowly = its weight $m g$	1
Work done $= m g \times h$	1
This work is stored as potential energy: $U = m g h$	1

A car of mass 1200 kg moving at 54 km/h is brought to rest by its brakes in a distance of 25 m. Find (a) its initial kinetic energy, (b) the work done by the brakes, (c) the average braking force. (4 marks)

Step	Marks
Convert: $54 \times \frac{5}{18} = 15$ m/s	1
(a) $K = \frac{1}{2} \times 1200 \times 1 5^{2} = 1.35 \times 1 0^{5}$ J	1
(b) $W = K_{2} - K_{1} = 0 - 1.35 \times 1 0^{5} = - 1.35 \times 1 0^{5}$ J (negative: the force opposes the motion)	1
(c) $F = \frac{1.35 \times 1 0 ^{5}}{25} = 5400$ N	1

Where students lose marks in Different Types of Energy

The slips examiners see most often, and what to write instead.

Mistake: Rote answer for a bell
CISCE examiners' comments, 2024: for a bell fixed on a cycle, candidates chose 'gravitational potential energy to sound' (because the bell is at a height) or 'electrical to sound' (recalling a doorbell).
Do this: A cycle bell is rung by moving a lever: kinetic (mechanical) energy → sound.
Usually costs: 1 mark.
Mistake: Wrong conversion for a candle
CISCE examiners' comments, 2025: candidates chose 'heat → chemical + light', treating the match flame as the input, or 'heat → kinetic + potential'.
Do this: The energy comes from the wax (fuel): chemical → heat + light.
Usually costs: 1 mark.
Mistake: Speed not converted to m/s
Using km/h in K = ½mv² gives an answer in the wrong units and wrong size, because the speed is squared.
Do this: Multiply km/h by 5/18 first.
Usually costs: 1 mark.
Mistake: Forgetting to square v
Writing K = ½mv instead of ½mv² makes every ratio wrong.
Wrong working
K = ½ × 0.5 × 4 = 1 J
Right working
K = ½ × 0.5 × 4² = 4 J
Do this: Write the formula first, then substitute.
Usually costs: 1 mark.

Practice questions on Different Types of Energy

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
The SI unit of kinetic energy is:
(a) watt
(b) joule
(c) newton
(d) kg m/s
Hint
All energies.
Answer
(b)
Q2 · 1 mark · MCQBoard level
The energy conversion in a microphone is:
(a) electrical to sound
(b) sound to electrical
(c) sound to heat
(d) mechanical to sound
Hint
It picks up your voice.
Answer
(b)
Q3 · 1 mark · MCQHarder board level
If the mass of a body is halved and its speed is doubled, its kinetic energy:
(a) stays the same
(b) doubles
(c) halves
(d) becomes four times
Hint
½ × 4.
Answer
(b)
Q4 · 1 mark · Assertion-reasonBoard level
Assertion (A): Water stored in a high dam has potential energy.
Reason (R): A body has potential energy because of its position, such as its height above a reference level.
(a) (A) is true and (R) is false.
(b) (A) is false and (R) is true.
(c) Both (A) and (R) are true, and (R) is the correct explanation for (A).
(d) Both (A) and (R) are true, but (R) is not the correct explanation for (A).
Hint
Position energy.
Answer
(c)
Q5 · 2 marks · Very short answerHarder board level
State the energy conversion in (a) an electric iron, (b) photosynthesis.
Hint
Before → after.
Answer
(a) Electrical → heat (b) Light → chemical
Q6 · 2 marks · Short answerHarder board level
A body of mass 2 kg has kinetic energy 100 J. Find its speed.
Hint
v = √(2K/m).
Answer
$v = \frac{200}{2} = 10$ m/s
Q7 · 3 marks · Long answerBoard level
(a) Define kinetic energy and potential energy. (b) Write their formulas. (c) Give one example of each.
Hint
Motion and position.
Answer
(a) KE: energy due to motion; PE: energy due to position or configuration. (b) K = ½mv²; U = mgh. (c) A moving car; a raised hammer (or a wound spring).
Q8 · 3 marks · Long answerHarder board level
A 10 kg box is raised from a shelf 2 m high to one 7 m high, then lowered to a ledge 1 m high. Find the change in PE in each step. ( $g = 10$ m s⁻²)
Hint
mg × change in height.
Answer
Raised: $10 \times 10 \times 5 = + 500$ J. Lowered from 7 m to 1 m: $10 \times 10 \times (- 6) = - 600$ J.
Q9 · 3 marks · Long answerHOTS / competency
The kinetic energy of a car increases by 125%. By what percentage has its speed increased? Explain.
Hint
New KE = 2.25 × old KE.
Answer
$K^{'} = 2.25 K$ , so $v^{'} = 2.25 v = 1.5 v$ : the speed increases by 50%.
Q10 · 3 marks · Long answerHarder board level
State the energy conversion in (a) ringing a bicycle bell, (b) a burning candle, (c) a bicycle dynamo.
Hint
Think start and end.
Answer
(a) Kinetic → sound (b) Chemical → heat + light (c) Mechanical (kinetic) → electrical
Q11 · 1 mark · MCQHOTS / competency
Two bodies of masses $m$ and $4 m$ have equal kinetic energies. The ratio of their speeds is:
(a) $1 : 2$
(b) $2 : 1$
(c) $1 : 4$
(d) $4 : 1$
Hint
v ∝ 1/√m.
Answer
(b)
Q12 · 4 marks · Long answerHOTS / competency
A force of 20 N acts on a 5 kg trolley at rest on a smooth floor and pushes it 10 m. (a) Find the work done. (b) Find the trolley's acceleration and final speed. (c) Show that its KE equals the work done.
Hint
v² = 2as.
Answer
(a) $W = 20 \times 10 = 200$ J. (b) $a = 4$ m s⁻²; $v^{2} = 2 \times 4 \times 10 = 80$ , $v \approx 8.94$ m/s. (c) $K = \frac{1}{2} \times 5 \times 80 = 200$ J = W.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Define potential energy.Show answer
Energy due to position or configuration of a body.
2.Formula for gravitational PE?Show answer
U = mgh
3.Formula for kinetic energy?Show answer
K = ½mv²
4.Three forms of kinetic energy?Show answer
Translational, rotational, vibrational.
5.Energy change in a microphone?Show answer
Sound → electrical.
6.Energy change in an electric motor?Show answer
Electrical → mechanical.
7.If speed triples, KE becomes?Show answer
Nine times.

Best order to study it

Forms of energy.
Potential energy, examples and derivation of U = mgh.
Kinetic energy and derivation of K = ½mv².
Forms of kinetic energy.
Numericals on U and K.
Energy conversions in devices and processes.

Quick revision checklist

The night before the exam: can you do each of these without looking?

Can you derive U = mgh and K = ½mv²?
Do you convert km/h to m/s?
Can you state the reference level for PE?
Can you name the conversion in ten devices?
Can you handle ratios with v²?

Different Types of Energy: frequently asked questions

Are rotational KE numericals in the ICSE syllabus?

No. Numerical problems are on K and U for translational motion only; rotational and vibrational KE need simple examples.

Can potential energy be negative?

Gravitational PE can be negative if the body is below the chosen reference level, but ICSE problems usually measure height above the ground.

Is elastic energy potential energy?

Yes. A stretched or compressed body has potential energy due to its configuration.

What is mechanical energy?

The sum of potential and kinetic energy of a body.

Which conversion happens in a cell?

When it supplies current, chemical energy changes into electrical energy.

Based on: CISCE ICSE 2027 Physics (Science Paper 1) syllabus; CISCE ICSE 2027 Physics (Science Paper 1) specimen question paper and marking scheme; CISCE Analysis of Pupil Performance, ICSE Physics (Science Paper 1), 2025; CISCE Analysis of Pupil Performance, ICSE Physics (Science Paper 1), 2024