Take a piece of thick wire bent in the form of a loop. It is passed at two points P and Q through horizontal cardboard as shown. The iron filings are sprinkled on the cardboard and current is allowed to flow through the battery. The observation(s) in the following experiment is\are
In the vicinity of wire at P and Q, the magnetic field lines are nearly circular
The magnetic field strength is increased if the strength of the current in the loop is increased
When current is passed through the coil, we find that the iron filings get arranged in a definite pattern representing magnetic field lines of the current carrying loop. In the vicinity of wire at P and Q, the magnetic field lines are nearly circular as iron filings arrange themselves in a circular pattern. On increasing the current, the iron filings get arranged in circles which are closer to each other and also upto a larger distance from the wire, showing the magnetic field strength has increased.