[" length should be : "],[" 10"cm],[" 15"cm],[" 20"cm],[" 0"30cm]

Column I (optical system ) Column II (focal length ) (P) 80 "cm" " " (Q) 40 "cm" " " (R) 30"cm" " " (S) 20"cm"

Column I (optical system ) Column II (focal length ) (P) 80 "cm" " " (Q) 40 "cm" " " (R) 30"cm" " " (S) 20"cm"

Column I (optical system ) Column II (focal length ) (P) 80 "cm" " " (Q) 40 "cm" " " (R) 30"cm" " " (S) 20"cm"

Find the perimeter : A table with sides equal to 30cm, 15cm, 30cm, and 15cm respectively.

The length breadth and height of two cuboids are 30 cm., 25 cm., 15cm. and 35cm., 20cm., 12cm. Compare their surface area. Which will have more volume?

In a rectangle,the length is longer than the breadth by 5cm. If theperimeter is 70cm, then the length and breadth are respectivelya) 15cm,20cmb)20cm,15cm c) 5cm,10cm d) 10cm,20cm

Find the volume of a box if its length, breadth and height are 20 cm, 10 cm and 30 cm respectively.

Height and base of a right angled triangle are 24 cm and 18 cm, find the length of its hypotenuse. a) 24cm b) 30cm c) 15cm d) 18cm

Four lenses of focal length +15 cm , +20 cm, +150 cm and +250cm are available for making an astronomical telescope. To produce the largest magnification, the focal length of the eye-piece should be