The correct answer is: D. prevent excessive temperature rise.
A heat sink is a passive heat exchanger that transfers heat away from a solid object to improve its thermal properties. It is typically made of metal and has a large surface area to maximize heat dissipation. Heat sinks are often used with transistors to prevent them from overheating.
Option A is incorrect because a heat sink does not increase the forward current. The forward current is the current that flows through a transistor when it is turned on. The forward current is determined by the transistor’s characteristics and the voltage applied to it.
Option B is incorrect because a heat sink does not decrease the forward current. The forward current is the current that flows through a transistor when it is turned on. The forward current is determined by the transistor’s characteristics and the voltage applied to it.
Option C is incorrect because a heat sink does not compensate for excessive doping. Doping is the process of adding impurities to a semiconductor material to change its electrical properties. A heat sink does not affect the doping of a semiconductor material.
I hope this helps! Let me know if you have any other questions.