2. Fundamentals of Electricity and Electronics —

What is the SI unit of electric current? A) Volt B) Ampere C) Ohm D) Watt

B) Ampere — The ampere measures electric current

What is the SI unit of voltage? A) Ohm B) Watt C) Volt D) Ampere

C) Volt — The volt measures electrical potential difference

What is the SI unit of electrical resistance? A) Ohm B) Ampere C) Joule D) Farad

A) Ohm — The ohm measures opposition to current flow

Which law relates voltage current and resistance? A) Newton law B) Ohm law C) Faraday law D) Boyle law

B) Ohm law — Voltage equals current multiplied by resistance

What is the formula for Ohm law? A) V = IR B) P = I/R C) R = VI D) I = VR

A) V = IR — Voltage equals current times resistance

A 12 V source is connected across a 6 ohm resistor. What current flows? A) 0.5 A B) 2 A C) 6 A D) 72 A

B) 2 A — Current equals voltage divided by resistance

A 10 ohm resistor carries 2 A. What is the voltage across it? A) 5 V B) 12 V C) 20 V D) 22 V

C) 20 V — Voltage equals current multiplied by resistance

A 24 V supply produces 3 A through a load. What is the resistance? A) 8 ohms B) 12 ohms C) 21 ohms D) 72 ohms

A) 8 ohms — Resistance equals voltage divided by current

What is the SI unit of electrical power? A) Joule B) Watt C) Volt D) Coulomb

B) Watt — Watt measures the rate of electrical energy transfer

Which formula calculates electrical power? A) P = VI B) P = V + I C) P = R/I D) P = V/R

A) P = VI — Power equals voltage multiplied by current

A device operates at 10 V and draws 2 A. What is its power? A) 5 W B) 12 W C) 20 W D) 100 W

C) 20 W — Power equals voltage times current

Which component stores electrical energy in an electric field? A) Resistor B) Capacitor C) Fuse D) Switch

B) Capacitor — A capacitor stores charge and energy in an electric field

What is the unit of capacitance? A) Henry B) Farad C) Tesla D) Ohm

B) Farad — The farad measures capacitance

Which component stores energy in a magnetic field? A) Inductor B) Capacitor C) Fuse D) Diode

A) Inductor — An inductor stores energy in its magnetic field

What is the unit of inductance? A) Farad B) Henry C) Watt D) Ampere

B) Henry — The henry measures inductance

What does a resistor primarily do? A) Stores magnetic energy B) Opposes current flow C) Generates oxygen D) Amplifies all signals

B) Opposes current flow — Resistance limits current and produces a voltage drop

What is the main function of a fuse? A) Increase voltage B) Store charge C) Interrupt excessive current D) Measure temperature

C) Interrupt excessive current — A fuse opens a circuit when current exceeds its rated limit

What does a diode generally allow? A) Current in one direction B) Equal current in every direction C) No voltage ever D) Unlimited current

A) Current in one direction — A conventional diode conducts mainly in its forward direction

What is the main function of a light emitting diode? A) Convert electrical energy into light B) Store magnetic energy C) Measure resistance D) Interrupt all current

A) Convert electrical energy into light — An LED emits light when appropriately forward biased

What does a transistor commonly do? A) Amplify or switch signals B) Measure body temperature only C) Store fuel D) Replace every resistor

A) Amplify or switch signals — Transistors are used for electronic switching and amplification

What is a semiconductor? A) A material whose conductivity can be controlled B) A perfect insulator under all conditions C) A mechanical fuse D) A type of battery

A) A material whose conductivity can be controlled — Semiconductor conductivity can be altered by doping temperature or applied fields

Which material is commonly used in semiconductor devices? A) Silicon B) Wood C) Rubber only D) Paper

A) Silicon — Silicon is widely used to manufacture electronic components

What is direct current? A) Current that periodically reverses direction B) Current that flows in one direction C) Current that has no electrons D) Current that exists only in capacitors

B) Current that flows in one direction — DC maintains a single direction of current flow

What is alternating current? A) Current that periodically reverses direction B) Current that always remains zero C) Current with no voltage D) Current only in batteries

A) Current that periodically reverses direction — AC changes direction periodically

What is the unit of frequency? A) Volt B) Hertz C) Ohm D) Farad

B) Hertz — Hertz measures cycles per second

An AC supply has a frequency of 60 Hz. What does this mean? A) 60 cycles per second B) 60 volts per second C) 60 ohms per second D) 60 watts total

A) 60 cycles per second — Frequency is the number of cycles completed each second

What is the period of a 50 Hz signal? A) 2 ms B) 20 ms C) 50 ms D) 100 ms

B) 20 ms — Period equals one divided by frequency

Which instrument measures voltage? A) Ammeter B) Voltmeter C) Ohmmeter D) Tachometer

B) Voltmeter — A voltmeter measures potential difference

Which instrument measures current? A) Ammeter B) Barometer C) Thermometer D) Hygrometer

A) Ammeter — An ammeter measures current and is connected in series for ordinary current measurement

How is a voltmeter normally connected to a component? A) In series B) In parallel C) Only to ground D) Across an open fuse only

B) In parallel — A voltmeter measures the potential difference across a component

How is an ammeter normally connected to measure branch current? A) In parallel across the supply B) In series with the branch C) Across a capacitor only D) Without completing the circuit

B) In series with the branch — Current must pass through the ammeter

What should you do before measuring resistance with a multimeter? A) Energize the circuit at full voltage B) Isolate power and discharge stored energy safely C) Short the mains supply D) Remove the meter fuse

B) Isolate power and discharge stored energy safely — Resistance measurements are generally made on de-energized circuits

What does continuity mode check? A) Whether an electrical path exists B) The patient's blood type C) The frequency of light D) The battery chemistry

A) Whether an electrical path exists — Continuity mode checks for a low-resistance electrical path

What is the purpose of a transformer? A) Change AC voltage levels B) Convert resistance into temperature directly C) Store data permanently D) Eliminate all electrical hazards

A) Change AC voltage levels — A transformer transfers energy between windings by electromagnetic induction

Which transformer increases voltage from primary to secondary? A) Step-down transformer B) Step-up transformer C) Isolation fuse D) Current-limiting resistor

B) Step-up transformer — A step-up transformer has a higher secondary voltage than primary voltage

What is the main purpose of a rectifier? A) Convert AC to DC B) Convert heat to sound C) Measure resistance D) Increase frequency to infinity

A) Convert AC to DC — Rectifiers use diodes or other devices to produce unidirectional output from AC

What does a filter capacitor do in a power supply? A) Reduce voltage ripple B) Increase ripple deliberately C) Replace grounding D) Measure current

A) Reduce voltage ripple — A filter capacitor smooths rectified voltage by storing and releasing charge

What is a battery's primary function? A) Convert stored chemical energy into electrical energy B) Convert sound directly into resistance C) Measure voltage automatically D) Eliminate short circuits

A) Convert stored chemical energy into electrical energy — Batteries supply electrical energy through electrochemical reactions

What is a short circuit? A) An unintended low-resistance path B) A correctly rated resistor C) A normal open switch D) A high-resistance insulator

A) An unintended low-resistance path — A short circuit can cause excessive current and overheating

What is the purpose of electrical grounding? A) Provide a safety path for fault current B) Increase shock risk intentionally C) Replace all insulation D) Guarantee zero voltage in every situation

A) Provide a safety path for fault current — Protective grounding helps reduce shock risk by providing a fault-current path

What does an insulation resistance tester evaluate? A) Insulation resistance B) Blood pressure C) Sound intensity D) Fluid viscosity

A) Insulation resistance — It checks electrical insulation using a specified test voltage

Which unit is commonly used for high insulation resistance? A) Milliliter B) Megaohm C) Degree Celsius D) Decibel

B) Megaohm — One megaohm equals one million ohms

What is an electrostatic discharge? A) Sudden transfer of static electric charge B) Slow mechanical rotation C) Normal fluid flow D) A temperature calibration

A) Sudden transfer of static electric charge — ESD can damage sensitive electronic components

What is the purpose of an antistatic wrist strap when properly used? A) Reduce static buildup on personnel B) Increase body voltage C) Replace medical isolation D) Measure AC frequency

A) Reduce static buildup on personnel — A properly grounded ESD strap helps equalize potential and control static discharge

What does a UPS provide during a power interruption? A) Temporary backup power B) Unlimited permanent electricity C) Automatic medical diagnosis D) Guaranteed surge-free output

A) Temporary backup power — An uninterruptible power supply provides backup power for a limited period

Why is a battery backup important for some medical equipment? A) It can maintain operation during a power outage B) It removes the need for maintenance C) It makes every device waterproof D) It eliminates all electrical testing

A) It can maintain operation during a power outage — Backup power helps maintain essential functions when mains power fails

What does a printed circuit board provide? A) Mechanical support and electrical connections for components B) Oxygen for patients C) Hydraulic pressure only D) A replacement for all sensors

A) Mechanical support and electrical connections for components — A PCB connects electronic components through conductive tracks

What is soldering used for in electronics? A) Join conductive parts electrically and mechanically B) Measure blood glucose directly C) Increase insulation resistance D) Calibrate every sensor automatically

A) Join conductive parts electrically and mechanically — Solder forms electrical and mechanical joints between compatible metal surfaces

What is a sensor? A) A device that detects a physical quantity B) A fuse that always resets C) A battery charger only D) A device that prevents all errors

A) A device that detects a physical quantity — Sensors respond to quantities such as temperature pressure or light

What is an analog signal? A) A signal that varies continuously B) A signal limited to two logic states only C) A signal that cannot carry information D) A mechanical fastener

A) A signal that varies continuously — Analog signals represent changing quantities over a continuous range

What is a digital signal commonly represented by? A) Discrete logic levels B) Continuous values only C) Fluid pressure only D) Magnetic poles without electronics

A) Discrete logic levels — Digital circuits commonly encode information using discrete states such as 0 and 1

What is the purpose of an analog-to-digital converter? A) Convert an analog signal into digital data B) Convert digital data into heat only C) Increase resistance to infinity D) Replace all power supplies

A) Convert an analog signal into digital data — An ADC samples and quantizes an analog input into digital values

Why should a biomedical technician verify a multimeter's leads and fuse before use? A) To improve safety and measurement reliability B) To increase the circuit voltage C) To bypass protective devices D) To avoid checking the measurement range

A) To improve safety and measurement reliability — Damaged leads or a blown fuse can cause unsafe conditions or invalid measurement