While measuring the length of a knitting needle, the reading of the scale at one end is3.0 cm and at the other endf is 33.1 cm. What is the length of the needle ?

The length of a rectangle is 7.1 cm and its breadth is 2.5 cm. What is the area of the rectangle?

The area of a trapezium is 34 cm^2 and the length of one of the parallel sides is 10 cm and its height is 4 cm. Find the length of the other parallel side.

Mahesh wanted to measure the length of his table top in metre.He had a 50 cm scale.He found that the length of the table top was 156 cm.What will be its length in metres?

A piece of ductile metal is in the formof a cylinder of diameter 1 cm and length 5 cm. It is drawn out into a wire of diameter 1 mm. What will be the length of the wire so obtained ?

A needle placed 45cm from a lens forms an image on the screen placed 90cm on the other side of the lens. What is the type of lens ? Find the focal length. If the length of needle is 5cm. What is the length of image ?

The figure TBQ 9.38 shows an equiconvex lens (of refractive index 1.50) in contact with a liquid layer on top of a plane mirror. A small needle with its tip on the principal axis is moved along the axis until its inverted images if found at the positions of hte needle. The distance of the needle from the lens is measured to be 45.0 cm. The new distane is measured to be 30.0 cm. What is the refractive index of the liquid?

The lengths of two sides of a triangle are 12 cm and 15 cm. Between what two measures should the length of the third side fall?