Dia. of driver pulley (D1) = 80cm
Dia. of follower pulley (D2) = 40cm
Dia. of driver pulley (D3) = 100cm
Dia. of follower pulley (D4) = 20cm
Slip on each drive, s1 = s2 = 2.5
Let N4 = Speed of the dynamo shaft
(i) When there is no slip
Using equation
N4/N1 = (D1.D3)/(D2.D4)
N4 = N1 X (D1.D3)/(D2.D4)
= [(80 X 100) X 200]/(40 X 20)
N4 = 2000RPM
(ii) When there is a slip of 2.5% at each drive In this case we will have the equation of:
N4/N1 = [(D1.D3)/(D2.D4)][1–s1/100][1–s2/100] Putting all the values, we get
N4 = N1 X [(D1.D3)/(D2.D4)][1– s1/100][1– s2/100]
N4 = 200 X [(80 X 100)/(40 X 20)][1 – 2.5/100][1– 2.5/100]
N4 = 1901.25R.P.M