In seven-segment display interfaces, resistors—typically about 300 Ω each—are placed in series between the decoder outputs and the display segments primarily to act as ________.

Introduction / Context:
Seven-segment LED displays require controlled current per segment to ensure proper brightness and to protect the LEDs. Decoder/driver ICs present logic-level outputs, but the LED segments themselves are current-driven devices. The series resistors placed between decoder outputs and LED segments have a specific, critical role in this interface.

Given Data / Assumptions:

• Typical series resistor value: around 300 Ω (value depends on supply voltage and desired segment current).
• Device: LED-based seven-segment display.
• Driver: BCD-to-7-segment decoder/driver or similar logic outputs.

Concept / Approach:
Light-emitting diodes are diodes with a forward voltage drop. Without a series element, current would be excessive when driven from a logic output or supply. A resistor in series enforces Ohm’s law to set segment current within safe limits, establishing both protection and consistent brightness.

Step-by-Step Solution:

Verification / Alternative check:
Measure segment current with an ammeter; verify brightness is even across segments. Thermal and datasheet limits must not be exceeded. Uniform brightness across all segments confirms correct resistor selection.

Why Other Options Are Wrong:

• Pull-up resistors: Used to define logic levels on inputs, not to limit LED current.
• Sense resistors: Used for measuring current, usually very low values and not for LEDs here.
• Surge resistors/snubbers: More relevant to power lines or inductive loads; LEDs are not inductive.
• Snubber resistors: Typically paired with capacitors for inductive transients, not applicable.

Common Pitfalls:
Driving LEDs directly from logic without resistors; using one resistor for common anode/cathode lines when per-segment control is required; ignoring driver sink/source current limits.

Final Answer:
current limiting resistors for the 7-segment display