Question

the input power to motor is 300w in 20s it lifts a load of 400N through height of 6m what is efficiency of motor​

Answer 1

Answer:

C

Explanation:

p= energy/time

p.e: mgh

p.e: (400/10)×10×6

p.e=2400

p= 2400/20

p=120

efficency= useful output/ useful input × 100

efficency= 120/300 × 100

efficency= 40%

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Answer 2

Answer:

40 %

Explanation:

Input Power = 300 W

Time = 20 s

Force = 400 N

Height = 6 m

Output Power = W/ t = F.h / t

                         = ( 400 ) ( 6 ) / 20

                         = 120 W

Efficiency = Output / Input

                 = 120 / 300 ( 100 )

                 = 40 %