19. 66 cubic centimetres of silver is drawn into a wire 1 mm in diameter. The length of the wire in metres will be:
A. 84
B. 90
C. 168
D. 336
Answer:
Option : A
Let the length of the wire be h m
Radius
|
=
|
|
1
|
|
mm
|
=
|
|
1
|
|
cm
|
2
|
20
|
Then,
⇒
|
|
22
|
x
|
1
|
x
|
1
|
x h
|
|
= 66
|
7
|
20
|
20
|
⇒
|
h
|
=
|
|
66 x 20 x 20 x 7
|
|
= 8400 cm
|
= 84 m
|
22
|
