Which component is used to amplify small output current from a logic circuit to drive a high-current load?

• A. Transistor
• B. Amplifier
• C. Antenna
• D. Circuit diagrams

Answer: (A)

To drive a high-current load from a small logic output, you need a device that can control a larger current with a smaller input. A transistor fits this role because its output current is controlled by a much smaller input current or voltage at the base or gate. In a bipolar transistor, the base current determines a much larger collector current (I_C ≈ β I_B), so a small logic signal can switch or drive a heavier load current. This makes the transistor an effective current amplifier or driver stage between the logic circuit and the load. An amplifier in general could provide gain, but the specific component that provides the actual current boost for interfacing with a high-current load is the transistor. Antenna and circuit diagrams don’t provide this current amplification.