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.

Two circular coils of radii 10 cm and 40 cm and equal number of turns are connected in series to a battery. The ratio of magnetic fields at their centres is

Two circular coils of radii 10 cm and 40 cm and equal number of turns are connected in series to a battery. The ratio of magnetic fields at their centres is

Two current carying circular coils A and B, having the same number of turns are connected in series. What is the ratio of the magnetic inductions produced at their centres, in the diameters of A and B are 10 cm and 20 cm respectively ?

Two circular coils are made from a uniform wire the ratio of radii of circular coils are 2.3 & no. of turns is 3:4. If they are connected in parallel across a battery. A.: Find ratio of magnetic induction at their centres. B: Find the ratio magnetic moments of 2 coils

Two circular coils are made from a uniform wire the ratio of radii of circular coils are 2:3 & no. of turns is 3:4 . If they are connected in parallel across a battery. A: Find ratio of magnetic inductions at their centres B: Find the ratio magnetic moments of 2 coils.

In the following figure a current loop is shown which is made from two circular arcs of radii a and b (a lt b) , connected by radial wires. Calculate the magnetic field at the centre O.

Two charged conducting spheres of radii r_1 and r_2 connected to each other by a wire. Find the ratio of electric fields at the surface of the two spheres.