Question

Draw a diagram to show the pattern of magnetic field lines on a horizontal sheet of paper due to a straight conductor passing through its centre and carrying current vertically upwards. Mark on it (i) the direction of current in the conductor and (ii) the corresponding magnetic field lines. State right hand thumb rule and check whether the directions marked by you are in accordance with this rule or not.

Answer 1

Diagram Description:
Visualize a horizontal paper with a straight conductor passing through its center, carrying current vertically upward (out of the page). The resulting magnetic field lines are concentric circles on the paper's plane.

Diagrammatic representation:
- A dot (•) at the center signifies upward current (out of the page).
- Concentric circular arrows around the dot depict the magnetic field lines.
- These arrows are drawn counterclockwise.

Markings:
(i) Current direction: Vertically upward (indicated by a central dot on the sheet).
(ii) Magnetic field lines: Concentric circles, counterclockwise, around the conductor.

Right-Hand Thumb Rule:
Hold a current-carrying conductor with your right hand so your thumb aligns with the current. Your fingers' curl direction indicates the magnetic field line direction.

Verification:
With upward current (out of the paper), the thumb points up. The curled fingers demonstrate a counterclockwise direction, confirming accurate magnetic field line representation.

Conclusion:
The depicted current direction and magnetic field pattern are consistent with the right-hand thumb rule.