Question

A circular disc is rotating about its own axis at the rate of $200$ revolutions per minute. Two particles P, Q of the disc are at distances $5cm$ and $10cm$ respectively from the axis of rotation. The ratio of angular velocities of P and Q is:

• A. $1:2$
• B. $1:1$
• C. $2:1$
• D. $4:1$

Answer 1

Answer: (B)

$1:1$

Since P and Q are of the same body, the angular velocity of both the particles, P and Q will be the same, which is equal to the angular velocity of the disc.
So, ${\omega }_P={\omega }_Q$
or, $\frac{{\omega }_P}{{\omega }_Q}=1$