ECAT Physics — Work and Energy
Work and Energy is part of the Physics section of the UET ECAT (30 of the 100 MCQs). It breaks into 3 subtopics, and we hold 33 ECAT-pattern practice MCQs on it, each with a written explanation. Tap a subtopic below to practise just that.
Subtopics (3)
How Work and Energy is tested
Across the 7 ECAT past papers on ParhaiKrlo, Work and Energy accounts for 11 questions. It appears in 5 of them, about 2.2 questions a paper. The heaviest was ECAT Past Paper 04, with 3 questions, and the most recent is ECAT Past Paper 07, with 2.
| Paper | Questions |
|---|---|
| ECAT Past Paper 07 | 2 |
| ECAT Past Paper 04 | 3 |
| ECAT Past Paper 03 | 1 |
| ECAT Past Paper 02 | 3 |
| ECAT Past Paper 01 | 2 |
Work and Energy MCQs from the ECAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · ECAT Past Paper 07 · Work and Energy
A 500 kg rocket travels in deep space at a constant speed of 3000 m/s. The power being produced by the rocket engine at this time is:
- A.1500 kW
- B.0.16 kW
- C.6 kW
- D.None of these
Show answer
Answer: D. None of these — No gravity or drag in deep space, so no thrust is needed for constant velocity: the power is zero.
- Q2 · ECAT Past Paper 04 · Work and Energy
A 500 kg rocket travels in deep space at a constant speed of 300 m/s. The power being produced by the rocket engine at this time is:
- A.1500 kW
- B.0.16 kW
- C.6 kW
- D.None of these
Show answer
Answer: D. None of these — In deep space there is no gravity or drag to overcome, so no thrust is needed for constant velocity: the engine power is zero.
- Q3 · ECAT Past Paper 03 · Work and Energy
The SI unit of power is the watt. It is defined as:
- A.One kilojoule of work done in one second
- B.One joule of work done in one hour
- C.One kilojoule of work done in one hour
- D.None of the above
Show answer
Answer: D. None of the above — 1 watt = 1 joule of work done per second, which is not among A–C.