Correct Answer - Option 3 : 340 rpm
Explanation:
Let us assume the power transmitted by belt from shaft to the engine is same i.e. neglect the friction loss.
So, power transmitted by shaft = power transmitted to engine
i.e. (Tω)shaft = (Tω)engine
Velocity of belt to the shaft = velocity of shaft to the engine
Vshaft = Vengine
\((\frac{\pi DN}{60})_{shaft}=(\frac{\pi DN}{60})_{engine}\)
\({DN}_{shaft}={DN}_{engine}\)
Calculation:
Given:
Dshaft = 30 cm, Dengine = 51 cm, Nengine = 200 rpm
51 × 200 = Nshaft × 30
Nshaft = 340 rpm