Electrical Systems Questions Flashcards
What does the term “short circuit” refer to?
a) A broken wire in a circuit
b) An unintended connection causing excessive current flow
c) A circuit with no load
d) A circuit operating at low voltage
b) An unintended connection causing excessive current flow
Which device is used to protect circuits from overcurrent?
a) Capacitor
b) Resistor
c) Circuit breaker
d) Transformer
c) Circuit breaker
What is the purpose of a multimeter?
a) Measure mechanical force
b) Test hydraulic pressure
c) Measure electrical properties such as voltage, current, and resistance
d) Align components in a circuit
c) Measure electrical properties such as voltage, current, and resistance
What is the difference between AC and DC current?
a) AC flows in one direction; DC alternates direction
b) AC alternates direction; DC flows in one direction
c) AC has higher voltage; DC has lower voltage
d) AC is used in batteries; DC is used in power grids
b) AC alternates direction; DC flows in one direction
What is the function of a relay in an electrical circuit?
a) To step up or step down voltage
b) To control a high-current circuit using a low-current signal
c) To store electrical energy
d) To measure electrical resistance
b) To control a high-current circuit using a low-current signal
What does a capacitor do in an electrical circuit?
a) Increases resistance
b) Stores electrical energy
c) Reduces current
d) Converts AC to DC
b) Stores electrical energy
Which device is used to measure current in a circuit?
a) Voltmeter
b) Ammeter
c) Ohmmeter
d) Oscilloscope
b) Ammeter
What is the purpose of a fuse in an electrical circuit?
a) To regulate voltage
b) To store energy
c) To protect against overcurrent
d) To measure resistance
c) To protect against overcurrent
What is the function of a step-down transformer?
a) Increase voltage
b) Decrease voltage
c) Increase current
d) Convert AC to DC
b) Decrease voltage
What does an open circuit indicate?
a) Current is flowing
b) Voltage is zero
c) There is a break in the circuit
d) Resistance is high
c) There is a break in the circuit
What is the purpose of an insulator in an electrical system?
a) To conduct electricity efficiently
b) To prevent electrical current from passing through
c) To increase the resistance in the circuit
d) To measure voltage
b) To prevent electrical current from passing through
What does a rectifier do in an electrical circuit?
a) Converts DC to AC
b) Converts AC to DC
c) Stores electrical energy
d) Reduces resistance
b) Converts AC to DC
What is the primary purpose of a circuit diagram?
a) To measure electrical resistance
b) To visually represent an electrical system
c) To troubleshoot electrical faults
d) To test voltage in a circuit
b) To visually represent an electrical system
What is the unit of electrical resistance?
a) Ampere
b) Volt
c) Ohm
d) Watt
c) Ohm
Which component is used to temporarily store electrical energy in a circuit?
a) Resistor
b) Capacitor
c) Inductor
d) Transformer
b) Capacitor
What happens to current flow if resistance increases in a circuit?
a) Current decreases
b) Current increases
c) Current stays the same
d) Voltage decreases
a) Current decreases
What is the purpose of grounding in an electrical system?
a) To increase voltage
b) To provide a safe path for stray current
c) To reduce resistance in a circuit
d) To measure current flow
b) To provide a safe path for stray current
What is a common symptom of an overloaded circuit?
a) Flickering lights
b) Low resistance
c) Decreased current flow
d) Reduced voltage
a) Flickering lights
Which tool is used to locate faults in an electrical cable?
a) Insulation tester
b) Cable tracer
c) Clamp meter
d) Oscilloscope
b) Cable tracer
What is the function of an inductor in an electrical circuit?
a) To store energy in a magnetic field
b) To reduce resistance
c) To convert AC to DC
d) To step up voltage
a) To store energy in a magnetic field
If a circuit has a voltage of 12V and a resistance of 4 ohms, what is the current flowing through the circuit?
a) 2A
b) 3A
c) 4A
d) 6A
b) 3A
(Explanation: Using Ohm’s Law: I = V / R = 12V / 4\u03a9 = 3A)
What is the voltage across a circuit with a resistance of 10 ohms and a current of 2A?
a) 5V
b) 10V
c) 20V
d) 50V
c) 20V
(Explanation: V = I \u00d7 R = 2A \u00d7 10\u03a9 = 20V)
If a circuit has a current of 5A and a voltage of 15V, what is the resistance in the circuit?
a) 2 ohms
b) 3 ohms
c) 5 ohms
d) 10 ohms
b) 3 ohms
(Explanation: R = V / I = 15V / 5A = 3\u03a9)
What happens to the current if the voltage is doubled and the resistance remains constant?
a) The current is halved
b) The current remains the same
c) The current is doubled
d) The current is reduced to zero
c) The current is doubled
(Explanation: According to Ohm’s Law, I = V / R. If V doubles and R remains constant, I will double.)
A circuit draws a current of 2A with a power supply of 24V. What is the total power consumed by the circuit?
a) 12W
b) 24W
c) 48W
d) 96W
c) 48W
(Explanation: Power (P) = Voltage (V) \u00d7 Current (I) = 24V \u00d7 2A = 48W)