Aptitude - Volume and Surface Area - Discussion
Discussion Forum : Volume and Surface Area - General Questions (Q.No. 4)
4.
66 cubic centimetres of silver is drawn into a wire 1 mm in diameter. The length of the wire in metres will be:
Answer: Option
Explanation:
Let the length of the wire be h.
| Radius = | 1 | mm | = | 1 | cm. | Then, |
| 2 | 20 |
 |
22 | x | 1 | x | 1 | x h = 66. |
| 7 | 20 | 20 |
| h = |
 |
66 x 20 x 20 x 7 |  |
= 8400 cm = 84 m. |
| 22 |
Discussion:
35 comments Page 3 of 4.
Archana said:
9 years ago
@Adil.
Formula of volume of cylinder is Pi * r * r * h.
Formula of volume of cylinder is Pi * r * r * h.
Adil said:
10 years ago
Please tell the formula.
Uma said:
10 years ago
How we know that the wire convert into cylinder form, may be its convert other shapes.
Rohini said:
1 decade ago
They have given d diameter. But we need radius. So when 1 mm is divided by 2, we get 1/2 mm and to convert mm into cm we have to multiply it by 10.
Therefore, 1/2 multiply by 10, we get 1/20.
Therefore, 1/2 multiply by 10, we get 1/20.
(1)
Megha said:
1 decade ago
Still I didn't get how we get 1/20? Please explain me step by step.
Gautam singh said:
1 decade ago
1cm = 10 millimeter.
To convert km into cm we have to multiply it by 10.
To convert km into cm we have to multiply it by 10.
Hi everybody said:
1 decade ago
Actaully wire is of the form:: CYCLINDER
we know,
volume of cyclinder = π*r^2* h----------- (1)
r-radius
h-height(lenth)
Given
Diameter(d)=1mm
so r=d/2
r=(1/2)mm
r=(1/20)cm
Substitute in Eqn (1)
22/7 * (1/20)^2 *h =66 (given)
h =66 x 20 x 20 x 7/22
= 8400 cm = 84 m.
we know,
volume of cyclinder = π*r^2* h----------- (1)
r-radius
h-height(lenth)
Given
Diameter(d)=1mm
so r=d/2
r=(1/2)mm
r=(1/20)cm
Substitute in Eqn (1)
22/7 * (1/20)^2 *h =66 (given)
h =66 x 20 x 20 x 7/22
= 8400 cm = 84 m.
Mystery said:
1 decade ago
@Ayush.
Because the wire is so small people don't tend to think of it as a cylinder but it is.
It is long and has very small radius!
Because the wire is so small people don't tend to think of it as a cylinder but it is.
It is long and has very small radius!
Ayush said:
1 decade ago
Please tell why the shape of wire is considered as cylinder?
Deepi said:
1 decade ago
@ Rashmi,
1cm=10milimeter
to convert mm into cm we have to multiply it by 10
1cm=10milimeter
to convert mm into cm we have to multiply it by 10
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