Calculate the specific rotation if the plane of polarisation is turned thorugh `13.2^@`, transversing a length of 20 cm of 10% sugar solution.

The resistance of a 0.5M solution of an electrolyte was found to be 30Omega . Calculate the molar conductivity of the solution if the electrods in the cell are 1.5 cm a part and having an area of cross section is 2.0 cm^(2) .

A small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . The current in the coil in (a) is switched off and the coil s positioned as shown in the figure. The coil is then turned thorugh an angle of 90^@ in a time of 0.14 s. Calculate the average e.m.f. induced in the coil.

Calculate the distance d,so that a real image of an object at O,15 cm in front of a convex lens of focl length 10 cm be formed at the same point O as sohwn in Fig.2.45. te radius of cuvature of the mirro is 20 cm.Will the image be inverted or erect? .

Calculate the conductivity of a wire of length 200 cm, area of cross-section 2cm^2 and of resistane 5xx10^4Omega .

A rectangular coil of area 5.0xx10^(-4) m^2 and 60 turns is pivoted about one of its vertical sides. The coil is in a radial horizontal field of 90 G (radial here means the field liners are in the plane of the coil for any rotation). What is the torsional constant of the hair spring connected to the coil if a current of 2.0 mA produces an angular deflection of 18^@ ?

Calculate the field due to an electric dipole of length 10 cm and consisting of charges of ne 100 muC at a point 20 cm from each charge.

Calculate the current in a circular coil of radius 5 cm and 100 turns to produce a field of 2 xx 10^-5 T at its centre.

A long solenoid of 10 turns / cm has a small loop of area 1 sq. cm placed inside with the normal of the loop parallel to the axis. Calculate the placed across the small loop if the current in the solenoid is changed from 1 A to 2 A in 0 .1 s, during the duration of this change.

Calculate the torque on a 100 turn rectangular coil of length 40 cm and breadth 20 cm, carrying a current of 10 A, when placed making an angle of 60^@ with a magnetic field of 5 T

Calculate the torque on a 50 turn circular coil of radius 10 cm, when placed with its plane at 60^@ with a magnetic field of 3.1 xx 10^-5 T . The current through the coil is 2 A.