Answer the following questions by selecting the correct/most appropriate options.

The difference between maximum and minimum resistance that can be obtained by connecting three resistances of 1/3 Ω each is:

What is the number of elements of the earth’s magnetic field?

Which of the following is INCORRECT statement about magnetic dipole moment?

Which one of the following graphs shows the magnetic field B inside and outside a current carrying long straight wire of a circular cross section of radius R (current uniformly distributed)?

What happens to magnetic fields when a material becomes superconducting and experiences the Meissner effect?