A 20kg mass is to be pulled up a slope inclined at 30° to the horizontal. If efficiency of the plane is 75%. The force required to pull the load up the plane is J [g=10ms\(^{− 2}\)]
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Correct Answer: Option C
Explanation:
V. R = \(\frac{1}{Sinθ}\)
 m = 20kg
 V.R = \(\frac{1}{Sin 30}\)
 = 2
 Efficiency = 75%
 Load = mg
 = 20 x 10 = 200N
 Efficiency = \(\frac{M.A}{V.R} \times 100\)
 75/100 = \(\frac{M.A}{2}\)
 M .A = \(\frac{75 \times 2}{100}\)
 M. A = 1.5
 Since M. A. = \(\frac{\text{Load}}{\text{Force}}\)
 Force = \(\frac{200}{1.5}\)
 = 133.3N
V. R = \(\frac{1}{Sinθ}\)
 m = 20kg
 V.R = \(\frac{1}{Sin 30}\)
 = 2
 Efficiency = 75%
 Load = mg
 = 20 x 10 = 200N
 Efficiency = \(\frac{M.A}{V.R} \times 100\)
 75/100 = \(\frac{M.A}{2}\)
 M .A = \(\frac{75 \times 2}{100}\)
 M. A = 1.5
 Since M. A. = \(\frac{\text{Load}}{\text{Force}}\)
 Force = \(\frac{200}{1.5}\)
 = 133.3N