Question
A sphere is melted to form 81 identical cylinders. If
radius of each cylindrical is 1/3rd of the radius of sphere and height of each cylinder is 4 cm, then find the radius of sphere.Solution
Let radius and height of each cylinder be ‘r’ cm. So, radius of sphere = 4r cm Volume of sphere = 81 × volume of each cylinder => (4/3)π(3r)3 = 81 × π × r2 × 4 => 9r = 81 => r = 9 So, required radius = 3r = 27 cm
“Hopper burn” is caused by brown plant hopper in _________ crop:
An extreme modification in the order Diptera, where hind wings are reduced to nubs used for balance and direction during flight is
Deficiency of which mineral causes interveinal chlorosis of older leaves in which the veins remain green but the area between them turns yellow
Jute fibre is obtained from
De suckering is practiced in
The Ranikhet disease affects:
Leaf curl disease of cotton is due to
Carbonation weathering involves reactions with:
Polyembryony occurs in
Which of the following is a measure to promote the export of organic products under India's Agricultural Export Policy?