What will happen to the output voltage in a series regulator, when temperature increases?

Explanation:

• When the temperature of a series voltage regulator increases, the output voltage tends to increase as well.
• This phenomenon is a result of the thermal characteristics of semiconductor devices used in series voltage regulators, such as transistors or integrated circuits.
• Here's why the output voltage increases with temperature in a series regulator:

Voltage Reference:

• Series voltage regulators typically use a voltage reference, such as a Zener diode or a precision voltage reference IC, to establish a stable output voltage.
• These voltage references have temperature-dependent characteristics.
• As the temperature rises, the reference voltage can increase slightly.

Transistor Characteristics:

• The pass transistor in a series regulator is responsible for regulating the output voltage.
• Transistors also have temperature-dependent characteristics, and their voltage drop across the collector-emitter junction can decrease as temperature rises.
• This reduced voltage drop means that less voltage is dropped across the pass transistor, resulting in a higher output voltage.

Feedback Loop:

• Series regulators use a feedback loop to maintain a constant output voltage.
• As the output voltage tends to increase due to the factors mentioned above, the feedback loop will adjust the control element (usually the base current of the pass transistor) to counteract this increase and maintain a stable output voltage.

Overall, the combination of these factors results in an increase in the output voltage when the temperature of a series regulator rises. This is why the correct answer is "Increases."