Applied Electrical Flashcards

If resistance remains the same and voltage is doubled in an AC circuit, then the current is _________.

Answer: Doubled

According to Ohm's Law (I = V/R), current is directly proportional to voltage when resistance is constant. If voltage doubles and resistance stays the same, current must also double. Quadrupling would only occur if voltage increased fourfold; halving would require voltage to decrease by half.

Prior to inning the tip with silver, the tip should be ______.

Answer: Wiped clean

Before tinning a soldering iron tip with solder or silver, the tip must be wiped clean to remove oxidation, old solder, and debris. A contaminated tip prevents proper heat transfer and causes poor solder joints. The other options — covering, running a full cycle, or flushing with saline — are not standard soldering preparation steps.

Which resistor will dissipate the least power when 2 resistors are parallel?

Answer: Larger Value Resistor

In a parallel circuit, voltage is the same across both resistors, so power dissipation is calculated as P = V²/R. A larger resistance value produces less power dissipation because power and resistance are inversely related at constant voltage. The smaller resistor carries more current and dissipates more power.

Every digital multimeter can measure 3 basic things: current, voltage, and ___________.

Answer: Resistance

Every digital multimeter (DMM) measures the three fundamental electrical quantities: voltage, current, and resistance. Resistance is the opposition to current flow, measured in ohms. An ammeter is a separate instrument, a resistor is a component, and isolation is not a basic DMM measurement.

Measure a current with this instrument.

Answer: Ammeter

An ammeter is the instrument specifically designed to measure electrical current in a circuit. It must be connected in series so all current flows through it. A voltmeter measures voltage (connected in parallel), a resistor is a component not an instrument, and an ampere is a unit of measurement, not an instrument.

The frequency range of an audio signal generator.

Answer: 20 to 20,000 Hz

The human ear can detect sound frequencies from approximately 20 Hz to 20,000 Hz (20 kHz), and audio signal generators are designed to cover this range. Ranges like 100–100,000 Hz or 5–200,000 Hz extend beyond normal human hearing, and '20 to 20,-5 Hz' is not a valid range.

The total power of a circuit.

Answer: Sum of the power dissipated by the resistors

The total power dissipated in a circuit equals the sum of the power dissipated by each individual resistor, by the conservation of energy. This applies to both series and parallel circuits. The other options — a grounded mat, an MSDS section, or just 'resistor' — are unrelated to the concept of total circuit power.

What fire extinguisher should be used on an electrical fire?

Answer: Class C

Class C fire extinguishers are rated for electrical fires because they use non-conductive extinguishing agents (such as CO₂ or dry chemical) that won't conduct electricity back to the user. Class A is for ordinary combustibles and Class B is for flammable liquids; 'Type C' is not an official classification distinct from Class C.

All of the connections that are shown on a schematic must be made in the copper on the printed circuit board.

Answer: Routing process

The routing process in PCB design is where the conductive copper traces are physically drawn on the board to connect all components as specified in the schematic. Isolation refers to separating circuits, bandwidth allocation is a networking concept, and forwarding relates to data packet transmission.

A ______transformer has more secondary turns than primary turns.

Answer: Step-up

A step-up transformer has more turns in the secondary coil than the primary coil, which increases the output voltage relative to the input. A step-down transformer does the opposite — fewer secondary turns, lower output voltage. Isolation transformers have a 1:1 turn ratio to electrically isolate circuits.

The period of given AC waveform is the time for one of these.

Answer: Full cycle

The period of an AC waveform is the time it takes to complete one full cycle — one complete oscillation from start back to the same point. It is the inverse of frequency (T = 1/f). A half cycle, a peak, or a zero crossing would each represent only a portion of the complete waveform.