Mastering Alternating Current (AC): Everything You Need to Know | HTET 2023

Welcome to our comprehensive guide on Alternating Current (AC) as part of your HTET 2023 exam preparation. AC is a fundamental concept in electrical engineering and plays a crucial role in our daily lives, powering everything from our homes to industries. Understanding AC is not only essential for acing your exam but also for gaining a deeper insight into the principles that drive modern electrical systems. In this blog, we'll demystify AC, covering its basics, key principles, and important applications. By the end of this guide, you'll be well-equipped to tackle AC-related questions on your HTET 2023 exam confidently. Let's dive into the world of Alternating Current! 

 1.  What is the frequency of standard household AC power in most countries?

a)      50 Hz
b)      60 Hz
c)       25 Hz
d)      100 Hz
 
2.       Which parameter defines the number of cycles per second in an AC waveform?
a)      Amplitude
b)      Frequency
c)       Phase
d)      Voltage
 
3.       In an AC circuit, what is the term for the maximum positive or negative value of the voltage or current waveform?
a)      Peak
b)      RMS
c)       Frequency
d)      Phase
 
4.       What is the unit of frequency for AC signals?
a)      Hertz (Hz)
b)      Volt (V)
c)       Ampere (A)
d)      Ohm (Ω)
 
5.       Which type of current alternates its direction periodically?
a)      DC current
b)      AC current
c)       Pulsating current
d)      Steady current
 
6.       In a purely resistive AC circuit, what is the phase angle between current and voltage?
a)      0 degrees
b)      45 degrees
c)       90 degrees
d)      180 degrees
 
7.       Which component of an AC circuit resists the flow of current?
a)      Inductor
b)      Capacitor
c)       Resistor
d)      Transformer
 
8.       Which component of an AC circuit stores energy in an electric field?
a)      Inductor
b)      Capacitor
c)       Resistor
d)      Transformer
 
9.       What is the mathematical relationship between voltage (V), current (I), and resistance (R) in an AC circuit?
a)      V = IR
b)      V = I/R
c)       V = I + R
d)      V = I * R
 
10.   What is the phase angle between voltage and current in a purely capacitive AC circuit?
a)      0 degrees
b)      45 degrees
c)       90 degrees
d)      180 degrees

11.   In an AC circuit with both resistance and inductance, what causes a phase difference between voltage and current?

a)      Resistance
b)      Inductance
c)       Capacitance
d)      Frequency
 
12.   Which device is used to measure AC voltage and current in a circuit?
a)      Ammeter
b)      Voltmeter
c)       Ohmmeter
d)      Multimeter
 
13.   What is the purpose of a transformer in an AC power distribution system?
a)      To convert AC to DC
b)      To change the frequency of AC
c)       To step up or step down voltage
d)      To store electrical energy
 
14.   What does the term "three-phase AC" refer to?
a)      A type of AC waveform with three peaks
b)      A system with three separate AC circuits
c)       A type of AC circuit with three resistors
d)      A system that uses three sinusoidal AC waveforms with a phase difference of 120 degrees
 
15.   What is the formula to calculate the apparent power (S) in an AC circuit?
a)      S = VI
b)      S = VR
c)       S = V/I
d)      S = V²/R
 
16.   In a series RL circuit, what happens to the phase angle as the inductance (L) increases?
a)      It decreases
b)      It remains the same
c)       It increases
d)      It becomes negative
 
17.   What is the SI unit of inductance?
a)      Volt (V)
b)      Ohm (Ω)
c)       Farad (F)
d)      Henry (H)
 
18.   What is the main advantage of AC over DC for long-distance power transmission?
a)      AC is safer
b)      AC is easier to generate
c)       AC can be easily stepped up or down in voltage
d)      AC has a lower power factor
 
19.   Which law describes the relationship between voltage, current, and resistance in an AC circuit?
a)      Ohm's Law
b)      Kirchhoff's Law
c)       Ampere's Law
d)      Faraday's Law
 
20.   What is the term for the maximum value of the instantaneous power in an AC circuit?
a)      Real power
b)      Apparent power
c)       Reactive power
d)      Peak power
21.   What is the name for a sudden, brief increase in voltage in an AC circuit?
a)      Surge
b)      Spike
c)       Brownout
d)      Sag
22.   In an AC circuit, what is the phase angle between voltage and current in a purely inductive circuit?
a)      0 degrees
b)      45 degrees
c)       90 degrees
d)      180 degrees
 
23.   Which component of an AC circuit opposes changes in the current by storing energy in a magnetic field?
a)      Inductor
b)      Capacitor
c)       Resistor
d)      Diode
 
24.   What is the power factor of a purely resistive AC circuit?
a)      0
b)      0.5
c)       1
d)      -1
 
25.   Which type of AC circuit exhibits a power factor of less than 1?
a)      Purely capacitive
b)      Purely resistive
c)       Purely inductive
d)      Series LC circuit
 
26.   What is the unit of capacitance?
a)      Ohm (Ω)
b)      Henry (H)
c)       Farad (F)
d)      Volt (V)
 
27.   In a capacitive AC circuit, how does the current waveform lead the voltage waveform in phase angle?
a)      The current lags behind the voltage
b)      The current is in phase with the voltage
c)       The current leads the voltage
d)      The current is unrelated to the voltage
 
28.   What type of circuit component allows current to flow in only one direction in an AC circuit?
a)      Capacitor
b)      Inductor
c)       Diode
d)      Resistor
 
29.   Which law states that the total voltage in a series AC circuit is equal to the sum of individual voltage drops?
a)      Ohm's Law
b)      Kirchhoff's Voltage Law
c)       Ampere's Law
d)      Faraday's Law
 
30.   What happens to the reactance of an inductor in an AC circuit as the frequency increases?
a)      It increases
b)      It decreases
c)       It remains the same
d)      It becomes zero
 
31.   In a parallel AC circuit with a resistor and a capacitor, how does the total impedance compare to the impedance of the individual components?
a)      Total impedance is greater than the impedance of either component
b)      Total impedance is equal to the impedance of the resistor
c)       Total impedance is equal to the impedance of the capacitor
d)      Total impedance is less than the impedance of either component

In conclusion, mastering the principles of Alternating Current is not just essential for your HTET 2023 exam; it's a foundational skill for anyone pursuing a career in electrical engineering or related fields. We've covered a wide range of AC concepts and provided you with valuable MCQs to reinforce your knowledge. Remember to practice regularly, consult your textbooks, and seek additional resources to solidify your understanding. As you prepare for your HTET 2023 exam, remember that success comes from dedication, thorough understanding, and problem-solving skills. Best of luck with your studies and your upcoming exam! You've got this!