Test on Semiconductor diode

Question 1: The primary function of a semiconductor diode is to amplify electrical signals.

A. Yes

B. No

Explanation: The study materials state that the semiconductor diode's unique property is allowing electric current to flow predominantly in one direction while blocking it in the opposite direction. It is essential for converting alternating current (AC) to direct current (DC), protecting circuits, and in various signal processing applications, but not primarily for amplifying electrical signals.

Question 2: Which of the following statements accurately describe characteristics of a P-type semiconductor?

A. It is created by doping a pure semiconductor with pentavalent impurities.

B. Its majority charge carriers are holes.

C. It is formed by doping with trivalent impurities such as boron or gallium.

D. It contributes extra free electrons, which act as negative charge carriers.

Explanation: P-type semiconductors are formed by doping with trivalent impurities (e.g., boron, gallium), which create 'holes' that act as positive charge carriers. Therefore, holes are the majority carriers in P-type material. Pentavalent impurities and extra free electrons are characteristic of N-type semiconductors.

Question 3: In the reverse bias region, the current flowing through the diode increases significantly with increasing reverse voltage before the breakdown voltage (U_BR) is reached.

A. Yes

B. No

Explanation: When a reverse voltage is applied, the current (I_R) remains extremely small (the reverse saturation current, I_S) and nearly constant, even as the reverse voltage increases, until the breakdown voltage (U_BR) is reached. The current only increases dramatically at U_BR.

Question 4: According to the I-V characteristic curve, what happens to the current in a diode when the reverse voltage reaches the breakdown voltage (U_BR)?

A. The current remains constant and very small.

B. The current suddenly increases dramatically in the reverse direction.

C. The current decreases to zero.

D. The current slowly increases linearly.

Explanation: The study materials state: 'At U_BR, the current suddenly increases dramatically in the reverse direction, often leading to diode destruction if not limited.' This indicates a rapid and significant increase in current at the breakdown voltage.

Question 5: Power grids supply alternating current (AC).

A. Yes

B. No

Explanation: The study materials state that 'power grids supply AC'.