Basic Electrical Circuits Questions and Answers Flashcards
6 cards from real MECHANICAL APTITUDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Basic Electrical Circuits Questions and Answers flashcards as text
What is the power dissipated by a 100Ω resistor with 2A flowing through it?
Answer: 400W
Power can be calculated using P = I²R. With 2A through a 100Ω resistor: P = (2)² × 100 = 4 × 100 = 400W.
What happens to the brightness of bulbs in a series circuit when one bulb is removed?
Answer: All remaining bulbs go out
In a series circuit, removing one component breaks the single current path, causing all remaining components to lose power. The circuit becomes open, and no current flows to any of the remaining bulbs.
Which type of current periodically reverses its direction of flow?
Answer: Alternating current (AC)
Alternating current (AC) periodically reverses direction, typically in a sinusoidal pattern. In most countries, AC power alternates at 50 or 60 Hz. Direct current flows in only one direction.
A wire's resistance increases when which of the following changes occurs?
Answer: The wire length increases
Resistance is directly proportional to the length of a conductor (R = ρL/A). Increasing the wire length increases the distance electrons must travel, resulting in more collisions with atoms and higher resistance.
What instrument is used to measure the voltage across a component in a circuit?
Answer: Voltmeter
A voltmeter measures the potential difference (voltage) across a component and is connected in parallel with the component being measured. An ammeter measures current and is connected in series.
In a circuit with a 9V battery and a total resistance of 3Ω, what is the current flowing through the circuit?
Answer: 3A
Using Ohm's Law (I = V/R): I = 9V / 3Ω = 3A. The current flowing through the circuit is 3 amperes.