Advertisements
Advertisements
प्रश्न
If each edge of a cuboid of surface area S is doubled, then surface area of the new cuboid is
पर्याय
2 S
4 S
6 S
8 S
Advertisements
उत्तर
Let,
l →Length of the first cuboid
b → Breadth of the first cuboid
h → Height of the first cuboid
And,
L → Length of the new cuboid
B → Breadth of the new cuboid
H → Height of the new cuboid
We know that,
L = 2l
B = 2b
H=2h
Surface area of the first cuboid,
S = 2(lb + bh +hl )
Surface area of the new cuboid,
S' = 2 (LB + BH + HI .)
=2 [(2l)(2b)+(2b)(2h)+(2h)(2l)]
=2 ( 4lb + 4 bh +4hl)
=4[2(lb+bh+hl)]
= 4S
The surface area of the new cuboid is 4S.
APPEARS IN
संबंधित प्रश्न
A cuboid is of dimensions 60 cm × 54 cm × 30 cm. How many small cubes with side 6 cm can be placed in the given cuboid?
Find the volume in cubic metre (cu. m) of the cuboid whose dimensions is length = 12 m, breadth = 10 m, height = 4.5 cm.
Find the surface area of a cuboid whose length = 10 cm, breadth = 12 cm, height = 14 cm.
Find the area of the cardboard required to make a closed box of length 25 cm, 0.5 m and height 15 cm.
A cloassroom is 11 m long, 8 m wide and 5 m high. Find the sum of the areas of its floor and the four walls (including doors, windows, etc.)
The external dimensions of a closed wooden box are 27 cm, 19 cm, and 11 cm. If the thickness of the wood in the box is 1.5 cm; find:
- The volume of the wood in the box;
- The cost of the box, if wood costs Rs. 1.20 per cm3;
- A number of 4 cm cubes that could be placed into the box.
A cube of edge 6 cm and a cuboid with dimensions 4 cm x x cm x 15 cm are equal in volume. Find:
(i) the value of x.
(ii) the total surface area of the cuboid.
(iii) the total surface area of the cube.
(iv) which of these two has a greater surface and by how much?
The height of a rectangular solid is 5 times its width and its length is 8 times its height. If the volume of the wall is 102.4 cm3, find its length.
A metallic sheet is of the rectangular shape with dimensions 48cm x 36cm. From each one of its corners, a square of 8cm is cutoff. An open box is made of the remaining sheet. Find the volume of the box.
The surface area of a cuboid formed by joining face to face 3 cubes of side x is 3 times the surface area of a cube of side x.
