A disc revolves with a spped of `33 (1/3) rev// min`, and has a radius of 15 cm. Two coins are placed at 4 cm and 14 cm away from the centre the record. If the co-effcient of friction between the coins and the record is 0.15, which of the coins will revolve with the record?

A gramophone record is revolving with an angular speed .A coin is placed at a distance r from the centre of the record.RThe coefficient of static friction is u.the coin will revolve with the record if :

Two charges +-10muC are placed 5.0 mm apart. Determine the electric field at a point on the axis of the dipole 15 cm away from its centre 0 on the side of the positive charge

A gramophone disc rotates at 60 revolutions per minute. A coin of mass 13 g is placed at the disc at a distance of 8.0 cm from the centre. Calculate centrifugal force on the coin.

A rectangular glass block of thickness 10 cm and refractive index 1.5 is placed over a small coin.A beaker is filled with water of refractive index 4//3 to a height of 10 cm and is placed over a small block. If the eye is slowly moved away from the normal at a certain position,the coin is found to diappear due to total internal reflection.At what surface does it happen and why? .

A double convex lens has 10 cm and 15 cm as its two radii of curvature.The image of an object,placed 30 cm from the lens,is formed at 20 cm from the lens on the other side.Find the refractive index of the material of the lens.Whgat will be the focal length ?What will be the focal length of the lens,if it is immersed in water of refractive index 1.33?

The length of a chord of a circle is 4 cm. If its perpendicular distance from the centre is 1.5 cm, determine the radius of the circle.

A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5.The distance of the virtual image from the surface of the sphere is

A chord of a circle of radius 15 cm subtends an angle of 60^@ at the centre. Find the areas of the corresponding minor and major segments of the circle. (Use pi = 3.14 and sqrt3 =1.73 )