NDA & CDS 1 2026 Exam Physics–Work, Power And Energy Class 8

Introduction

In Physics, the concepts of Work, Power and Energy help us understand how objects move and how forces affect motion. These concepts are closely related to our day-to-day activities such as walking, lifting objects, riding a bicycle, or operating machines. For example, when a soldier lifts equipment, pushes an obstacle, or runs with speed, the ideas of work done, energy used, and power applied come into play.

This chapter lays the foundation for higher-level Physics, which is very important for competitive examinations like NDA and CDS. A clear understanding of these basics helps students easily grasp advanced topics such as mechanics, laws of motion, and energy conservation in later classes.

Overview of the Chapter

1. Work
   • In Physics, work is said to be done only when a force causes displacement in the direction of the force.
   • Work = Force × Displacement
   • Situations where work is not done (e.g., pushing a wall that doesn’t move) are also discussed.
   • Unit of work: Joule (J)
2. Energy
   • Energy is the capacity to do work.
   • Types of energy covered:
     • Kinetic Energy – energy due to motion
     • Potential Energy – energy due to position or height
   • Examples related to real life and defence activities help in better understanding.
   • Unit of energy: Joule (J)
3. Power
   • Power tells us how fast work is done or how quickly energy is used.
   • Power = Work / Time
   • Unit of power: Watt (W)
   • Concept of average power is introduced.
4. Law of Conservation of Energy
   • Energy can neither be created nor destroyed; it only changes from one form to another.
   • This principle is very important for understanding machines, weapons, vehicles, and physical training in defence services.

Relevance for NDA CDS 1 2026 Exam

• Questions related to Work, Energy, and Power are frequently asked in NDA and CDS Physics sections, especially in basic conceptual and numerical form.
• Strong understanding at Class 8 level helps aspirants:
  • Solve numerical problems quickly
  • Avoid conceptual mistakes
  • Build confidence for higher Physics topics
• Topics like units, formulas, real-life applications, and basic calculations are highly exam-oriented.
• This chapter also improves logical thinking and problem-solving skills, essential for defence examinations.

Conclusion

The chapter Work, Power and Energy is one of the most important and scoring topics in Physics for NDA and CDS aspirants. It connects theoretical concepts with practical life and defence-related activities. By mastering the fundamentals of this chapter at the Class 8 level, students build a strong base for advanced Physics and competitive exams.

A disciplined approach—understanding definitions, learning formulas, practicing numericals, and applying concepts to real-life situations—will help aspirants perform well in the NDA CDS 1 2026 examination and move one step closer to their dream of serving the nation.