A wheel and axle is used to raise a load of 500 N by the application of an effort of 250 N. If the radii of the wheel and the axle are 0.4 cm and 0.1 cm respectively, the efficiency of the machine is
-
A.
20 % -
B.
40 % -
C.
50 % -
D.
60 %
Correct Answer: Option C
Explanation
Efficiency = M.A/V.R X 100/1 M.A = Load/Effort = 500/250
= 2
V.R. = radius of wheel/radius of axle = 0.4/0.1 = 4.
therefore Efficiency = 2/4 x 100/1 = 50 %