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Physics

Work, Energy and Power

A Physics chapter of the NEET syllabus, and how to practise it for the computer-based exam.

Exam rules change between cycles. Confirm dates, syllabus and pattern against NTA's official site. We are not NTA.

Weightage: what the paper actually did

Work, Energy and Power carried 3 questions in the NEET 2026 paper. One paper is a data point, not a destiny: NTA moves weight between chapters every cycle, which is why the weightage tables deserve care. The stable facts are the paper's shape: 180 questions, 720 marks, +4 right, −1 wrong.

Sample PYQs from this chapter

Real questions NTA asked from Work, Energy and Power, with the answer and the working. Try before you peek.

Question 1 · NEET 2026

A particle of mass MM moves along a horizontal xx axis from x=0x = 0 to x=Lx = L. The coefficient of kinetic friction varies as a function of xx as μk(x)=μ0−αx\mu_k(x) = \mu_0 - \alpha x, where μ0\mu_0, α\alpha are constants of appropriate dimensions, so that μk(L)=0\mu_k(L) = 0. The total work done by the frictional force during the motion is nμ0MgLn\mu_0 MgL, where gg is the acceleration due to gravity. The value of nn is:
  1. A.3
  2. B.1
  3. C.13\frac{1}{3}
  4. D.12\frac{1}{2}
Answer and explanation

Answer: D

The condition μk(L)=0\mu_k(L) = 0 fixes α=μ0/L\alpha = \mu_0/L, so μk(x)=μ0(1−xL)\mu_k(x) = \mu_0\left(1 - \frac{x}{L}\right) falls linearly from μ0\mu_0 to zero. Because the force varies with position, the work must be integrated: ∣W∣=∫0Lμk(x)Mg dx=μ0Mg[L−L2]=12μ0MgL|W| = \int_0^L \mu_k(x) Mg\,dx = \mu_0 Mg\left[L - \frac{L}{2}\right] = \frac{1}{2}\mu_0 MgL. Comparing with nμ0MgLn\mu_0 MgL gives n=1/2n = 1/2, which is simply the average of the initial and final friction coefficients since the variation is linear. NCERT Class 11, Work, Energy and Power (work done by a variable force).

Question 2 · NEET 2026

The power of a crane, which lifts a mass of 1000 kg to a height of 20 m in 10 s is: (g=9.8 m/s2g = 9.8\ \text{m/s}^2)
  1. A.19.6 W
  2. B.39.2 W
  3. C.19.6 kW
  4. D.39.2 kW
Answer and explanation

Answer: C

The useful power is work done against gravity divided by time, P=mghtP = \dfrac{mgh}{t}. Substituting, P=1000×9.8×2010=19600 W=19.6 kWP = \dfrac{1000 \times 9.8 \times 20}{10} = 19600\ \text{W} = 19.6\ \text{kW} (option C). The 19.6 W answer drops a factor of 1000, and the 39.2 values double-count g or the height.

How to practise Work, Energy and Power

Chapter by chapter, against real past-paper questions, on a screen: NEET is computer based from 2027. Read the chapter once, then attempt its PYQs until your accuracy stops climbing, and let the wrong answers tell you which lines to reread. If the chapter keeps refusing to stick, that has its own guide. There is also a free NEET mini mock with answers.

Nearby Physics chapters

Questions

How many questions did Work, Energy and Power have in NEET 2026?

Work, Energy and Power carried 3 questions in the NEET 2026 paper. Weightage shifts between cycles, so treat it as a probability, not a promise.

Where can I practise Work, Energy and Power PYQs for NEET?

Explore available chapter-wise NEET practice in BrainIt, free until the 2027 exam. Review explanations and track chapter accuracy to guide your revision. Sample questions from this chapter are on this page.

Is Work, Energy and Power important for NEET 2027?

It is part of the Physics syllabus the paper draws from, and NEET 2027 is computer based, so practise it on a screen. Your own accuracy in the chapter matters more than any weightage table: a heavy chapter you already score well on needs less time than a light one you keep missing.

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