Work, Energy and Power — Flashcards
NIOS · Class 12 · Physics
39 flashcards for Work, Energy and Power (NIOS Class 12 Physics) to test yourself on key terms and facts. Part of the NIOS Class 12 Physics syllabus.
Interactive on Super Tutor
Studying Work, Energy and Power? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for flashcards and more.
Free trial, no card needed.
One of 3 illustrations for Work, Energy and Power in Super Tutor — alongside flashcards, concept maps and practice questions.
State the definition and formula for Work done by a constant force. What is its SI unit?
Answer
Work done by a constant force F acting at angle θ with displacement d is: W = F · d · cos θ In vector form: W = F⃗ · d⃗ Key Points: • Work is a SCALAR quantity • If θ = 0°, W = Fd (maximum positive…
A force of 6 N is applied on an object at 60° with the horizontal. The object moves 2 m horizontally. Calculate the work done.
Answer
Given: F = 6 N, θ = 60°, d = 2 m Find: Work done W Formula: W = F · d · cos θ Solution: W = 6 × 2 × cos 60° W = 6 × 2 × 0.5 W = 6 J Answer: W = 6 J Note: Only the horizontal component (F cos60° =…
Why is no work done when you push a wall with all your strength but it does not move?
Answer
Because Work = F × d × cos θ, and displacement d = 0. W = F × 0 × cos θ = 0 J Even if force applied is very large, ZERO displacement means ZERO work done in the scientific sense. Real-world example…
A force F⃗ = (2î + 3ĵ) N produces a displacement d⃗ = (–î + 2ĵ) m. Calculate the work done.
Answer
Given: F⃗ = (2î + 3ĵ) N d⃗ = (–î + 2ĵ) m Formula: W = F⃗ · d⃗ Solution (Dot Product): W = (2)(–1) + (3)(2) W = –2 + 6 W = 4 J Answer: W = 4 J Note: Even though one component contributes negative w…
When is work done by gravity POSITIVE and when is it NEGATIVE? Explain with examples.
Answer
Work done by Gravity = mg × displacement × cos θ CASE 1 – Object moving DOWNWARD: • Force (mg) ↓ and displacement ↓ → θ = 0° • W_gravity = +mgh (POSITIVE) • Example: A stone falling from a building …
State Hooke's Law for a spring. Write the formula for work done in compressing or stretching a spring by distance x.
Answer
Hooke's Law: The restoring force in a spring is proportional to the displacement from equilibrium: F_s = –kx Where: • k = spring constant (N/m) • x = compression or extension (m) • Negative sign sho…
A mass of 2 kg is attached to a spring of force constant k = 100 N/m. Calculate the work done by an external force in stretching the spring by 10 cm.
Answer
Given: m = 2 kg, k = 100 N/m, x = 10 cm = 0.1 m Find: Work done W Formula: W = ½ k x² Solution: W = ½ × 100 × (0.1)² W = ½ × 100 × 0.01 W = 50 × 0.01 W = 0.5 J Answer: W = 0.5 J Note: Work done b…
Define Power. Write its formula, SI unit, and dimensional formula. How is kilowatt-hour (kWh) related to joules?
Answer
Power is the RATE of doing work. Average Power: P = W / t Instantaneous Power: P = dW/dt SI Unit: Watt (W) = Joule/second = J s⁻¹ Dimensional Formula: [ML²T⁻³] Other Units: • 1 kW = 10³ W • 1 MW …
+31 more flashcards
Practise AllFrequently Asked Questions
What are the important topics in Work, Energy and Power for NIOS Class 12 Physics?
How many flashcards are available for Work, Energy and Power?
How should I revise Work, Energy and Power for the NIOS Class 12 board exam?
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Work, Energy and Power
Practice Quiz
Test yourself with a quick quiz
Important Questions
Exam-style questions with answers
Revision Notes
Key points for last-minute revision
Formula Sheet
The chapter's formulas in one place
Chapter Summary
Understand the chapter at a glance
Concept Maps
See how topics connect
Study Plan
Step-by-step plan for this chapter
Syllabus
What topics to cover
For serious students
Get the full Work, Energy and Power chapter — start free.
Quizzes, flashcards, an AI doubt solver and a study plan for NIOS Class 12 Physics. Free to start, no card needed.