Identifying I-V characteristics of circuit components

Steps:

• Metal wire at constant temperature shows ohmic behavior: straight line through origin (resistance constant, I ∝ V).
• Semiconductor diode exhibits rectification: low current for reverse bias, exponential increase for forward bias (asymmetric curve).
• Filament lamp has resistance increasing with temperature: initial steep slope flattens as V rises (non-linear upward curve).
• Match graphs: Y (straight line) to wire, X (asymmetric) to diode, Z (flattening curve) to lamp.

Why B is correct:

• Option B assigns Y (ohmic straight line) to wire per Ohm's law (V = IR, constant R), X (rectifying asymmetry) to diode, and Z (temperature-dependent curve) to lamp.

Why the others are wrong:

• A: Swaps diode and lamp; diodes aren't symmetric curves.
• C: Assigns straight line to lamp; lamps aren't ohmic.
• D: Gives straight line to diode; diodes aren't linear.

Final answer: B