A circular hole of `2mm` in diameter and `8mm` deep in a metal block is rebored to increase the diameter to `2.12mm` ,then the amount of metal removed is approximately

A circular coil of 200 mm diameter is made of 100 turns of thin wire and carries a current of 50 mA. Find the magnetic field induction at the centre of the coil.

A metallic sphere 1 dm in diameter is beaten into a circular sheet of uniform thickness equal to 1 mm. Find the radius of the sheet.

A straight wilre of diameter 0.5 mm carrying a current 2A is replaced by another wire of diameter 1 mm carrying the same current. The strength of magnetic field at a distance 2 m away from the centre is

A piece of ductile metal is in the form of a cylinder of diameter 1cm and length 11 cm. It is drawn out into a wire of diameter 1mm. What will be the length of the wire so formed?

The radius of a metallic sphere is 60 mm .It is melted and recast in to wire of diameter 0.8 mm .Find the length of the wire.

When a load of 10 kg is suspended on a metallic wire, its length increase by 2 mm. The force constant of the wire is

A screw gauge with a pitch of 1 mm has 100 divisions on its circular scale. What it is used to measure the diameter of a thin wire, the main scale reading is 3 mm and the circular scale reading is 45. If D is the diameter of the wire in mm, then find the value of D.

Two large holes are cut in a metal sheet. If this is heated, will their diameters increase or decrease?

The circular scale of a screw gauge has 50. divisions and pitch of 0.5 mm. Main scale reading is 2. Find the diameter of sphere.

A wire of length 15m and diameter 4 mm elongates 0.3mm when stretched by weigth of 2.20kg. Calulate the Young's modulus of the material of the wire.