Question

An electric current flows along a wire PQ. The variation of current density is shown in the graph. Which of the following statements could explain the variation?

• A. The strip is narrower at P than at Q
• B. The strip is narrower at Q than at P
• C. Current at P is greater than current at Q
• D. Current at Q is greater than current at P

Answer 1

Answer: (A)

The strip is narrower at P than at Q

Answer 2

$\overset{\rightarrow}{E} = \rho\overset{\rightarrow}{J}$

where r – Resistivity

$\overset{\rightarrow}{J}$– current density

$|{\overset{\rightarrow}{J}}_{A}| > |{\overset{\rightarrow}{J}}_{B}|$

\ E_A > E_B