Question

What fraction of a clockwise revolution does the hour hand turn through when it rotates from?
a) 3 to 6
b) 6 to 12
[2 MARKS]

Answer 1

Each option: 1 Mark

We may observe that in one complete clockwise revolution, the hour hand will rotate through 360$\circ$
a) We have to find out the fraction of a clockwise revolution that an hour hand turns through when it rotates from 3 to 6.
Now, when the hour hand rotates from 3 to 6 it will rotate through 1 right angle.
$\therefore$ The fraction of revolution= $\frac{{90}^{\circ }}{{360}^{\circ }}$=$\frac{1}{4}$ revolution
b) Here the hour hand rotates from 6 to 12, which is to right angles.
$\therefore$ The fraction of revolution= $\frac{{180}^{\circ }}{{360}^{\circ }}$=$\frac{1}{2}$ revolution