Question

The diameter of a roller is 7 cm and its length is 40 cm. The area covered in one revolution is: 880 sq.Cm 1540 sq.Cm 957 sq.Cm none of these

Answer 1

r=3.5cm

h=40cm

CSA of cylinder=2πrh

=2*22/7*3.5*40

=44*0.5*40

=44*20= 880cm2