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
In a parallel circuit with three resistors of 10Ω, 20Ω, and 30Ω, which resistor carries the most current?
Answer: The 10Ω resistor
In a parallel circuit, voltage across each branch is equal. By Ohm's law (I = V/R), the resistor with the lowest resistance draws the most current. The 10Ω resistor has the least resistance, so it carries the most current.
What happens to the total resistance in a circuit when you add another resistor in parallel?
Answer: Total resistance decreases
Adding a resistor in parallel provides an additional path for current to flow, which always decreases the total resistance of the circuit. The total parallel resistance is always less than the smallest individual resistor.
A 12V battery is connected to a series circuit with two resistors. If the voltage drop across the first resistor is 8V, what is the voltage across the second resistor?
Answer: 4V
In a series circuit, the total voltage equals the sum of voltage drops across all components (Kirchhoff's Voltage Law). Since the battery provides 12V and 8V drops across the first resistor, the remaining 4V must drop across the second resistor.
Which component in a circuit stores energy in an electric field?
Answer: Capacitor
A capacitor stores energy in an electric field between its plates. Resistors dissipate energy as heat, inductors store energy in a magnetic field, and transistors act as switches or amplifiers.
What is the unit of electrical resistance?
Answer: Ohm
The ohm (Ω) is the SI unit of electrical resistance, named after Georg Simon Ohm. Amperes measure current, volts measure potential difference, and watts measure power.
In a circuit, what does a fuse protect against?
Answer: Excessive current
A fuse is a safety device designed to protect circuits from excessive current (overcurrent). It contains a thin wire or strip that melts and breaks the circuit when current exceeds a safe level, preventing damage to components or fire hazards.