Two toroids 1 and 2 have total number of turns 200 and 100 respectively with average radii 40cm and 20cm respectively. If they carry same current i, then the ratio of the magnetic fields along the two is :

Two flat circular coils A and B are made from two identical copper wires, each of length 50 cm. If the number of turns inA and B are 6 and 3 respectively, and the same current flows though them, then the ratio of the magnetic fields at the currents of A and B will be

A toroidal coil has 3000 turns. The inner and outer radii are 10 cm and 12 cm respectively. If current flowing is 5 A, then the magnetic field inside the toroid will be

Two circular coils made of similar wires but of radii 20 and 40cm are connected in parallel. Find the ratio of the magnetic fields at their centers.

Spheres A and B have their radii 40 cm and 10 cm respectively. Ratio of surface area of A to the surface area of B is :

A toroid consists of a coil wrapped around with 4 layers of windings of 300 turns each. The inner and outer radius of toroid are 10 cm and 15 cm, respectively. Il the coil carries a current of 15 A, find the maximum and minimum values of the magnetic field within the toroid.

The average radius of an air cored made toroid is 0.1 m and it has 500 turns. If it carries 0.5 ampere current, then the magnetic field inside it is :

Two concentric circular coils of five turns each are situated in the same plane. Their radii are 20 cm and 30 cm and they carry respectively 0.2 A and 0.3 A current in same direction. The magnetic field in tesla at the centre is

A toroid with mean radius r_(0) , diameter 2a have N turns carrying current l. What is the magnetic field B inside the the toroid?

Two circular copper coils of radii 10 cm and 20 cm and having the same number of turns, are connected in parallel. The two copper wires have the same area of cross-section. What is the ratio of the magnetic inductions at the centres of the coils ?