Basic Electricity NABTEB past questions and answers

Basic Electricity NABTEB past questions and answers

What does a voltmeter measure in an electrical circuit?

A) Voltage

B) Resistance

C) Current

D) Capacitance

Answer: A) Voltage

What is the term used to describe the opposition to the flow of alternating current in a circuit?

A) Reactance

B) Resistance

C) Conductance

D) Impedance

Answer: A) Reactance

Which law states that the total voltage in a series circuit is equal to the sum of individual voltages?

A) Ohm's Law

B) Kirchhoff's Voltage Law

C) Lenz's Law

D) Faraday's Law

Answer: B) Kirchhoff's Voltage Law

What is the symbol for an alternating current source in a circuit diagram?

A) ◻

B) ⎓

C) ~

D) ↦

Answer: C) ~

What device is used to protect sensitive electronic components from voltage spikes?

A) Fuse

B) Circuit Breaker

C) Surge Protector

D) Resistor

Answer: C) Surge Protector

Which law states that the direction of induced current in a circuit opposes the change in magnetic field that produced it?

A) Kirchhoff's Law

B) Lenz's Law

C) Faraday's Law

D) Ampere's Law

Answer: B) Lenz's Law

What does a transformer do in an electrical system?

A) Increases resistance

B) Converts DC to AC

C) Changes voltage levels

D) Stores electrical energy

Answer: C) Changes voltage levels

What is the role of a diode in an electrical circuit?

A) To store charge

B) To conduct electricity in both directions

C) To regulate voltage

D) To allow current flow in one direction

Answer: D) To allow current flow in one direction

Which component is used to smooth out variations in voltage in a circuit?

A) Capacitor

B) Resistor

C) Inductor

D) Transformer

Answer: A) Capacitor

What is the relationship between voltage, current, and resistance in a circuit according to Ohm's Law?

A) V = IR

B) I = VR

C) R = VI

D) V = I/R

Answer: D) V = I/R

Which material is often used as a semiconductor in electronic devices?

A) Copper

B) Aluminum

C) Silicon

D) Gold

Answer: C) Silicon

What is the unit of magnetic flux?

A) Weber

B) Tesla

C) Henry

D) Gauss

Answer: A) Weber

Which device converts mechanical energy into electrical energy?

A) Capacitor

B) Transformer

C) Generator

D) Inductor

Answer: C) Generator

What does an oscilloscope measure in an electrical circuit?

A) Voltage

B) Current

C) Frequency

D) Waveforms

Answer: D) Waveforms

What is the unit of electrical conductance?

A) Ohm

B) Farad

C) Siemens

D) Weber

Answer: C) Siemens

Which law states that the magnetic field induced around a current-carrying conductor is directly proportional to the current flowing through it?

A) Gauss's Law

B) Ampere's Law

C) Ohm's Law

D) Faraday's Law

Answer: B) Ampere's Law

What is the phenomenon where a material retains some magnetic properties after the magnetizing field is removed?

A) Induction

B) Hysteresis

C) Magnetization

D) Flux

Answer: B) Hysteresis

What property of a circuit represents the opposition to the flow of alternating current due to capacitance and inductance?

A) Resistance

B) Reactance

C) Conductance

D) Impedance

Answer: D) Impedance

Which component is used to increase or decrease the voltage in a circuit?

A) Resistor

B) Capacitor

C) Transformer

D) Inductor

Answer: C) Transformer

What does a rectifier do in an electrical circuit?

A) Converts AC to DC

B) Regulates voltage

C) Increases resistance

D) Stores electrical energy

Answer: A) Converts AC to DC