Electronics Information Practice Test 7

Correct answer: B — copper

Copper has high electrical conductivity and low resistance due to its abundant free electrons, making it one of the most widely used electrical conductors.

Correct answer: A — coulomb

The coulomb (C) is the standard SI unit of electric charge, defined as the amount of electric charge supplied by a current of one ampere for one second $$(1\text{ C} = 1\text{ A}\cdot\text{s})$$

Correct answer: D — voltmeter

A voltmeter is specifically designed to measure potential difference (voltage) between two points in a circuit and is always connected in parallel.

Correct answer: C — increases voltage while decreasing current

A step-up transformer increases the output voltage relative to the input while proportionally decreasing current, which reduces energy loss during long-distance transmission.

Correct answer: A — the presence and mobility of outer-shell free electrons

Conductors have loosely bound valence electrons (free electrons) that drift easily when an electric field is applied, whereas insulators have tightly bound electrons that resist movement.

Correct answer: B — converts DC to AC

An inverter is an electronic device or power conditioning unit that converts direct current (DC) into alternating current (AC) at a required voltage and frequency.

Correct answer: C — resistance

According to Ohm's law $$(R = \frac{V}{I})$$, the ratio between the electromotive force (voltage) and the current in a DC circuit is defined as resistance, measured in ohms (Ω).

Correct answer: B — alternating current

Commercial power grids transmit electricity as alternating current (AC) because its voltage can be easily stepped up or down using transformers for efficient long-distance distribution.

Correct answer: A — inductor

An inductor stores energy in its magnetic field $$(E = \frac{1}{2} L I^2)$$ when current flows through the coils, while a capacitor stores energy in the electric field between its conductive plates.

Correct answer: D — Volts Direct Current

VDC stands for Volts Direct Current, indicating a constant electric potential difference where charge carriers flow continuously in a single direction.

Correct answer: B — from positive to negative

Conventional current flow theory assumes positive charge carriers move from the positive terminal to the negative terminal, which is opposite to actual electron flow (negative to positive).

Correct answer: C — maintains a stable constant output voltage

A Zener diode is specially designed to allow current to flow in reverse when a specific Zener voltage is reached, making it ideal for maintaining a constant reference voltage.