the points X and Y, as shown in diagram in series with the battery, a plug and key. Sprinkle some iron filings uniformly on the cardboard. Keep the variable of the rheostat at a fixed position and note the current through the ammeter. Close the key so that a current flows through the wire. Ensure that the copper wire placed between the points X and Y remains vertically straight. Gently tap the cardboard a few times. Observe the pattern of the iron filings. It is observed that the iron filings align themselves showing a pattern of concentric circles around the copper wire. These represent the magnetic field lines.
(i) Right hand thumb rule
(ii) (a) Yes, alpha particles being positively charged constitutes a current in the direction of motion. A + +
(b) No, neutron being electrically neutral constitute no current.
