Rainbow 🌈 mind map snd MCQ pf Power

 Rainbow 🌈 mind map Power

Definition:  Rate of doing work 

Quantity: derived quantity

Units: SI- watt, other unit: HP

Relations:   1 watt = 1 J/s

                   1 HP = 746 W

Formula: power = work done/ time =  energy/ time

Factors affecting Power

• Amount  of Work done by the source 
• Time taken by the source to do the said work

Power and work: If it takes 20 s for a girl A to climb up the stairs white the other girl takes 15 s for the same job. 

Ratio of the work done = 1:1.

Ratio of power spent = 3:4

Rainbow 🌈 MCQ of Power

 

1.Power is measured 

 A) rate of change of Velocity 
 B) rate of change of displacement 
 C) rate of doing work. 
 D) None of these

ANSWER= (C) rate of doing work. 
Explain:- Work is definedas rate of doing work..

 

2. Power is 

 A) vector quantity 
 B) depending quantity 
 C) derived quantity 
 D) Fundamental quantity 

ANSWER= (C) derived quantity 
Explain:- Power is derived quantity. 

 

3. S.I unit of Power

 A) watt 
 B) Watt
 C) WATT
 D) all of above 

ANSWER= (A) watt 
Explain:- S.I unit of time is watt.

 

4. 1 H.P =  = _______ W

 A) 1
 B) 746
 C) 476
 D) 674

ANSWER= (B) 746
Explain:-1 H.P = 746 W

 

5.Power =  ______ 

 A) W+ t
 B) W x t
 C) W/ t
 D) E x t

ANSWER= (C) W/ t
Explain:-  Power = W/ t

 

6.Factors affecting Power

 A) Work done
 B) time taken 
 C) both
 D) None of above

ANSWER= (C) both
Explain: Factors affecting Power are - work done and time taken.

 

7. Time duration increases for any work done-

 A) Power of a body increases 
 B) Power of a body decreases 
 C) Power doesn't depend on time taken.
 D) none of above 

ANSWER= (B) Power of a body decreases 
Explain:- Power of a body is directly depended on amount of work and inversely proportional to time taken. 

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