Question

A gear system has the driving wheel of radius $2cm$ and driven wheel of radius $20cm$. If the number of rotations made per minute by the driving wheel is $100$, the number of rotations per minute made by the driven wheel will be :

• A. $10$
• B. $2$
• C. $4$
• D. $8$

Answer 1

The correct option is A $10$

$\text{Given}:$ $n_a=100$, $r_A=2cm$, $r_B=20cm$

$\text{Solution}:$

The number of rotations made per minute by the driving wheel is $n_a=100$

The number of rotations made per minute by the driven wheel

$n_b=\frac{r_A}{r_B}\times n_a=\frac{2}{20}\times 100=10$

$\text{Hence A is the correct option}$