Question

The length of the minute hand of a clock is 14 cm. The area swept by the minute hand in 15 minutes is

a) 144 cm^2
b)164 cm^2
c)154 cm^2
d)51.33 cm^2​

Answer 1

c

Explanation:

In 60 minutes, minute hand completes 360

0

i.e., one rotation.

⇒ in 1 minute, minute hands completes

60

360

∘

​

=6

∘

Hence, in 5 minutes the angle covered is is 6×5=30

o

.

The angle of sector formed is 30

o

.

The area swept by the minute hand in 5 minutes=

360

30

​

×π×14×14

Using π=

7

22

​

, we get

The area swept by the minute hand in 5 minutes =

3

154

​

sq. cm