1st Year Physics Chapter 4 Notes (New Book 2025-26): Work, Energy and Power – All Punjab Boards
Work, energy and power are words you use in daily life, and that is exactly what makes Chapter 4 tricky. In physics each of them has a precise meaning that does not always match ordinary speech, and many mistakes come from slipping back into the everyday sense. These notes support Chapter 4 of the new PECTAA Class 11 Physics book, which Punjab adopted from the 2025-26 session.
The file holds five parts: MCQs, short questions with answers, long questions with answers, numericals with worked solutions, and the textbook exercise solved. It is free, and you download it directly from this page.
Use notes made for the current book only. The textbook in use before 2025-26 divided Class 11 physics into a different set of chapters, and material from that course may not follow the new chapter’s questions or exercise.
Whether your board is in Sahiwal, Sargodha, Lahore, Faisalabad, Multan, Bahawalpur, Gujranwala, Rawalpindi or Dera Ghazi Khan, this file is meant for you. The rest of this page sets out the role of each part, shows how the parts line up with the paper, and suggests a way to study a chapter where exact terms and careful calculation go hand in hand.
About Chapter 4 in brief
Work, Energy and Power, as the title suggests, deals with three closely related physical quantities. In broad terms, it describes how energy is transferred and how quickly that transfer takes place. This page is a guide to the notes; it does not attempt to teach the chapter.
What’s inside the 1st year physics chapter 4 notes
Chapter 4’s file is organised into five parts. Here is what each part is for and how you can work with it.
MCQs
The MCQs on Chapter 4 test whether you hold the physics meaning of each term firmly. Options in this chapter can be phrased to sound right in everyday language while being wrong in physics, so they reward careful thinking.
Do one set in the morning and the same set again a few days later. If the same questions trip you up both times, an idea probably needs another look in the textbook. Keep a short list of those ideas and clear it one by one.
Short questions with answers
Here you get short questions paired with answers. Typical short questions on this chapter ask for a definition, a unit, a condition under which something holds, or a brief explanation of an observation.
In this chapter, a short answer often depends on getting one word exactly right. As you go through the answers in the notes, underline the term that carries the meaning. When you write your own, make sure that term appears and that you have used it in its physics sense.
Long questions with answers
The long-question section gives extended answers. Long questions on work, energy and power can ask you to explain a principle with reasoning, show how one quantity is related to another, or describe a process in a logical order.
Try explaining one answer aloud to a classmate or a family member before writing it. Speaking forces you to put the stages in order, and gaps become obvious when you cannot move from one step to the next. Then write the answer down and check it against the notes.
Numericals (solved)
Numerical problems on Chapter 4, with solutions, make up this part. Questions here often combine a formula with a unit conversion or ask you to work out an intermediate value before the final one.
Begin your own attempt by listing the given quantities with their units and stating clearly what you need to find. Write the formula in symbols first, then substitute. If a problem has two stages, finish the first stage and label its result before you start the second. When you check your work against the solution, look at the stages separately so you can see which one went wrong.
Solved exercise
In this part, the textbook’s end-of-chapter exercise is solved. That exercise gathers the kinds of questions the chapter wants you to master, which is why it is a dependable source of practice for tests.
Mix up the order when you use it. Instead of going from the first question to the last, pick items at random, attempt them, and then check. Practising out of order is closer to what happens in a test, where questions do not arrive in the sequence of the textbook.
Why these notes are useful
The file helps you pair exact understanding with careful working, which is what this chapter asks for.
- Follows the 2025-26 book. The notes are prepared for Chapter 4 of the new PECTAA textbook.
- Help with precise terms. Short answers and MCQs push you to use each term in its physics sense.
- Worked problems to compare with. Solved numericals and the solved exercise let you check each stage of your own working.
- Free to download. There is no fee to download the file here.
No set of notes can replace regular practice. Use the file alongside the textbook and your teacher’s explanations, and let your own attempts come first.
Which exam questions these notes help with
This table connects each part of the notes with a question type commonly found in the intermediate physics paper. The pattern, number of questions and marks are set by your board, so consult its official pairing scheme for the current session.
| Part of the notes | Paper question type |
| MCQs | Objective-type multiple-choice questions |
| Short questions with answers | Short-answer questions in the subjective paper |
| Long questions with answers | Long descriptive questions |
| Numericals (solved) | Calculation-based problems in the subjective paper |
| Solved exercise | Questions taken from or similar to the textbook exercise |
Shortcut lists that promise the “important” Chapter 4 questions are not issued by any board. Treat them with caution; working through the chapter and exercise, then reading the pairing scheme, is the more reliable route.
How to study with these notes
Clear definitions come first in this chapter, and problem practice builds on them. A suggested order:
- Read the chapter and collect the definitions. Write each main term with its physics meaning and unit on one sheet.
- Contrast with everyday meanings. Beside each term, note one way the daily-life sense differs from the physics sense.
- Attempt the book’s exercise. Do the questions in rough, out of order if you like.
- Compare each answer with its solution. Find the exact step where any answer differs.
- Solve the numericals. For each problem, write the given data, the unknown, the formula in symbols and the units, then substitute and compare with the solution.
- Practise the written answers. Explain a long answer aloud, then write it; rewrite a few short answers from memory.
- Round off with the MCQs. Repeat the set after a few days and focus on questions you missed twice.
Keep your sheet of definitions short enough to read in five minutes. It makes a handy review before any test on this chapter.
Who should use these notes
These notes are intended for Class 11 physics students in Punjab who use the new textbook introduced in 2025-26. FSc pre-engineering and pre-medical students form the main group, and other students with physics under a Punjab board, including private candidates, are welcome to use them too.
Confirm with your college or board that the new edition is the one set for your session.
Download the notes
Get the 1st year physics chapter 4 notes free from this page; the download does not send you to any other website.
Keep your definitions sheet with the file so the two can be revised together.
Frequently asked questions
Are these the notes for Chapter 4 of the new PECTAA book?
Yes. They follow Chapter 4, Work, Energy and Power, in the Class 11 Physics textbook used in Punjab from 2025-26.
Why are definitions in this chapter easy to get wrong?
Usually because the everyday meaning of a word slips into the answer. Learn the physics meaning of each term and use that exact sense when you write.
Does the file have solved numericals?
Yes. One part of the file is devoted to solved numericals, alongside MCQs, short and long questions with answers, and the solved exercise.
Can I study the parts in any order?
You can, but trying the textbook exercise before reading its solutions usually teaches you more than reading the solutions first.