1. Q: What is voltage? ANSWER Voltage is the electrical potential difference
between two points, measured in volts (V). It represents the force that pushes
electric current through a conductor.
2. Q: What is Ohm's Law? ANSWER Ohm's Law states that voltage (V)
equals current (I) multiplied by resistance (R): V = I × R.
3. Q: What is the unit of electrical current? ANSWER Ampere (A) or amp,
which measures the flow of electric charge per unit time.
4. Q: What is resistance? ANSWER Resistance is the opposition to current
flow in an electrical circuit, measured in ohms (Ω).
5. Q: What is the difference between AC and DC? ANSWER AC
(Alternating Current) periodically reverses direction, while DC (Direct Current)
flows in one constant direction.
6. Q: What is impedance? ANSWER Impedance is the total opposition to
current flow in an AC circuit, combining resistance and reactance, measured in
ohms.
7. Q: What does a capacitor do? ANSWER A capacitor stores electrical
energy in an electric field and can block DC while allowing AC to pass.
8. Q: What is the function of an inductor? ANSWER An inductor stores
energy in a magnetic field and opposes changes in current flow.
9. Q: What is a diode? ANSWER A diode is a semiconductor device that
allows current to flow in only one direction.
10. Q: What is grounding in electrical systems? ANSWER Grounding
provides a safe path for electrical current to flow to earth, protecting against
electric shock and equipment damage.
11. Q: What is a short circuit? ANSWER A short circuit is an unintended
low-resistance connection between two points in a circuit, causing excessive
current flow.
,12. Q: What is an open circuit? ANSWER An open circuit is a break in the
electrical path that prevents current from flowing.
13. Q: What is power in electrical terms? ANSWER Power is the rate of
energy transfer, measured in watts (W), calculated as P = V × I.
14. Q: What is the difference between series and parallel circuits?
ANSWER In series circuits, components are connected end-to-end with one
path for current. In parallel circuits, components are connected across common
points with multiple current paths.
15. Q: What is a transistor? ANSWER A transistor is a semiconductor
device used to amplify or switch electronic signals and electrical power.
16. Q: What is frequency in AC circuits? ANSWER Frequency is the
number of complete cycles per second, measured in Hertz (Hz).
17. Q: What is a transformer? ANSWER A transformer is a device that
transfers electrical energy between circuits through electromagnetic induction,
typically changing voltage levels.
18. Q: What is the purpose of a fuse? ANSWER A fuse protects circuits by
melting and breaking the circuit when current exceeds a safe level.
19. Q: What is a circuit breaker? ANSWER A circuit breaker is a resettable
protective device that automatically interrupts current flow when it exceeds safe
limits.
20. Q: What is RMS voltage? ANSWER RMS (Root Mean Square) voltage
is the effective value of AC voltage, equivalent to DC voltage that would
produce the same power.
21. Q: What is inductive reactance? ANSWER Inductive reactance is the
opposition to AC current flow caused by inductance, increasing with frequency.
22. Q: What is capacitive reactance? ANSWER Capacitive reactance is the
opposition to AC current flow caused by capacitance, decreasing with
frequency.
23. Q: What is a LED? ANSWER A Light Emitting Diode (LED) is a
semiconductor device that emits light when current flows through it.
24. Q: What is the purpose of a rectifier? ANSWER A rectifier converts AC
to DC by allowing current to flow in only one direction.
, 25. Q: What is a relay? ANSWER A relay is an electrically operated switch
that uses an electromagnet to mechanically operate switching contacts.
26. Q: What is skin effect? ANSWER Skin effect is the tendency of AC
current to flow primarily near the surface of a conductor at high frequencies.
27. Q: What is a Zener diode used for? ANSWER A Zener diode is used for
voltage regulation, maintaining a constant voltage across its terminals when
reverse-biased.
28. Q: What is the color code for a 10kΩ resistor? ANSWER Brown,
Black, Orange, and then tolerance band (typically Gold for 5% or Silver for
10%).
29. Q: What is conductance? ANSWER Conductance is the reciprocal of
resistance, measuring how easily current flows, measured in siemens (S).
30. Q: What is an optocoupler? ANSWER An optocoupler is a device that
transfers electrical signals using light, providing electrical isolation between
circuits.
31. Q: What is electromagnetic interference (EMI)? ANSWER EMI is
unwanted electromagnetic radiation that can disrupt the operation of electronic
equipment.
32. Q: What is a varistor? ANSWER A varistor (voltage-dependent resistor)
is a component that protects circuits from voltage spikes by changing resistance
with voltage.
33. Q: What is the difference between analog and digital signals?
ANSWER Analog signals vary continuously over time, while digital signals
have discrete values, typically represented as binary (0s and 1s).
34. Q: What is a SCR (Silicon Controlled Rectifier)? ANSWER An SCR is
a semiconductor device that acts as a switch, conducting when triggered and
continuing until current drops below a threshold.
35. Q: What is phase angle in AC circuits? ANSWER Phase angle is the
difference in timing between voltage and current waveforms in an AC circuit.
36. Q: What is a potentiometer? ANSWER A potentiometer is a variable
resistor with three terminals used for voltage division or resistance adjustment.
between two points, measured in volts (V). It represents the force that pushes
electric current through a conductor.
2. Q: What is Ohm's Law? ANSWER Ohm's Law states that voltage (V)
equals current (I) multiplied by resistance (R): V = I × R.
3. Q: What is the unit of electrical current? ANSWER Ampere (A) or amp,
which measures the flow of electric charge per unit time.
4. Q: What is resistance? ANSWER Resistance is the opposition to current
flow in an electrical circuit, measured in ohms (Ω).
5. Q: What is the difference between AC and DC? ANSWER AC
(Alternating Current) periodically reverses direction, while DC (Direct Current)
flows in one constant direction.
6. Q: What is impedance? ANSWER Impedance is the total opposition to
current flow in an AC circuit, combining resistance and reactance, measured in
ohms.
7. Q: What does a capacitor do? ANSWER A capacitor stores electrical
energy in an electric field and can block DC while allowing AC to pass.
8. Q: What is the function of an inductor? ANSWER An inductor stores
energy in a magnetic field and opposes changes in current flow.
9. Q: What is a diode? ANSWER A diode is a semiconductor device that
allows current to flow in only one direction.
10. Q: What is grounding in electrical systems? ANSWER Grounding
provides a safe path for electrical current to flow to earth, protecting against
electric shock and equipment damage.
11. Q: What is a short circuit? ANSWER A short circuit is an unintended
low-resistance connection between two points in a circuit, causing excessive
current flow.
,12. Q: What is an open circuit? ANSWER An open circuit is a break in the
electrical path that prevents current from flowing.
13. Q: What is power in electrical terms? ANSWER Power is the rate of
energy transfer, measured in watts (W), calculated as P = V × I.
14. Q: What is the difference between series and parallel circuits?
ANSWER In series circuits, components are connected end-to-end with one
path for current. In parallel circuits, components are connected across common
points with multiple current paths.
15. Q: What is a transistor? ANSWER A transistor is a semiconductor
device used to amplify or switch electronic signals and electrical power.
16. Q: What is frequency in AC circuits? ANSWER Frequency is the
number of complete cycles per second, measured in Hertz (Hz).
17. Q: What is a transformer? ANSWER A transformer is a device that
transfers electrical energy between circuits through electromagnetic induction,
typically changing voltage levels.
18. Q: What is the purpose of a fuse? ANSWER A fuse protects circuits by
melting and breaking the circuit when current exceeds a safe level.
19. Q: What is a circuit breaker? ANSWER A circuit breaker is a resettable
protective device that automatically interrupts current flow when it exceeds safe
limits.
20. Q: What is RMS voltage? ANSWER RMS (Root Mean Square) voltage
is the effective value of AC voltage, equivalent to DC voltage that would
produce the same power.
21. Q: What is inductive reactance? ANSWER Inductive reactance is the
opposition to AC current flow caused by inductance, increasing with frequency.
22. Q: What is capacitive reactance? ANSWER Capacitive reactance is the
opposition to AC current flow caused by capacitance, decreasing with
frequency.
23. Q: What is a LED? ANSWER A Light Emitting Diode (LED) is a
semiconductor device that emits light when current flows through it.
24. Q: What is the purpose of a rectifier? ANSWER A rectifier converts AC
to DC by allowing current to flow in only one direction.
, 25. Q: What is a relay? ANSWER A relay is an electrically operated switch
that uses an electromagnet to mechanically operate switching contacts.
26. Q: What is skin effect? ANSWER Skin effect is the tendency of AC
current to flow primarily near the surface of a conductor at high frequencies.
27. Q: What is a Zener diode used for? ANSWER A Zener diode is used for
voltage regulation, maintaining a constant voltage across its terminals when
reverse-biased.
28. Q: What is the color code for a 10kΩ resistor? ANSWER Brown,
Black, Orange, and then tolerance band (typically Gold for 5% or Silver for
10%).
29. Q: What is conductance? ANSWER Conductance is the reciprocal of
resistance, measuring how easily current flows, measured in siemens (S).
30. Q: What is an optocoupler? ANSWER An optocoupler is a device that
transfers electrical signals using light, providing electrical isolation between
circuits.
31. Q: What is electromagnetic interference (EMI)? ANSWER EMI is
unwanted electromagnetic radiation that can disrupt the operation of electronic
equipment.
32. Q: What is a varistor? ANSWER A varistor (voltage-dependent resistor)
is a component that protects circuits from voltage spikes by changing resistance
with voltage.
33. Q: What is the difference between analog and digital signals?
ANSWER Analog signals vary continuously over time, while digital signals
have discrete values, typically represented as binary (0s and 1s).
34. Q: What is a SCR (Silicon Controlled Rectifier)? ANSWER An SCR is
a semiconductor device that acts as a switch, conducting when triggered and
continuing until current drops below a threshold.
35. Q: What is phase angle in AC circuits? ANSWER Phase angle is the
difference in timing between voltage and current waveforms in an AC circuit.
36. Q: What is a potentiometer? ANSWER A potentiometer is a variable
resistor with three terminals used for voltage division or resistance adjustment.
