Question

There is a thin metal plate of length, breadth and thickness 2M mm, 2K mm and 1 mm respectively. If ‘N’ number of plates are placed one on top of the other, what is the object formed and what is its volume in $m{m}^3$?

• A. Cuboid, MKN
• B. Cuboid, 4MKN
• C. Sphere, 4MKN
• D. Cylinder, 2 MKN

Answer 1

The correct option is B

Cuboid, 4MKN

Thickness of 1 plate = 1mm.
Total thickness of N plates put together = N mm

The object formed has now 3 dimensions- Length, breadth and thickness.
The area of one plate $=\text{Length}\times \text{Breadth}$
$=2M\times 2K$
$=4MKm{m}^2$
The object formed when thin plates are stacked together is nothing but a cuboid. This can be visualised as shown below.


$\text{Volume}=\text{Area}\times \text{Thickness}$
$=4MK\times N$
$=4MKNm{m}^3$