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WorksheetsAC circuit 2
Total questions: 69
Worksheet time: 43mins
________ is used to cover electric wires.
rubber
copper
iron
Which of these is an insulator ?
wood
gold
iron
Capacitive susceptance is a measure of
Reactive power in a circuit
The extent of neutralization of reactive power in a circuit
A purely capacitive circuit's ability to pass current
A purely capacitive circuit's ability to resist the flow of current
The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is
4 kVAR
6 kVAR
8 kVAR
2 kVAR
Pure inductive circuit takes power from the A.C. line when
Applied voltage decreases but current increases
Applied voltage increases but current decreases
Both applied voltage and current increase
Both applied voltage and current decrease
Which of the following statements pertains to resistors only?
Can dissipate considerable amount of power
Oppose sudden changes in voltage
Connecting them in parallel increases the total value
Both (a) and (b)
In an AC. circuit, a low value of kVAR compared with kW indicates
Low efficiency
High power factor
Unity power factor
Maximum load current
A heater is rated as 230 V, 10 kW, 50 Hz AC. The value 230 V refers to
Average voltage
r.m.s. voltage
Peak voltage
None of the above
The time constant of a series R-C circuit is given by
R/C
RC2
R2C
RC
In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will
Be reduced by half
Be doubled
Be four times as high
Be reduced to one fourth
In an A.C. circuit power is dissipated in
Resistance only
Inductance only
Capacitance only
In all the three passive elements
All the rules and laws of D.C. circuit also apply to A.C. circuit containing
Capacitance only
Inductance only
Resistance only
All above
If two sinusoids of the same frequency but of different amplitudes and phase angles are subtracted, the resultant is
A sinusoid of double the frequency
A sinusoid of the same frequency
A sinusoid of half the original frequency
None of the above
Definitions of power factor of a series R-L-C circuit are correct except
Ratio of net reactance and impedance
Ratio of kW and kVA
Ratio of R and Z
Ratio of W and VA
The steady or DC current which when flowing through a circuit for a given time period produces the same heat as produced by the AC current flowing through the same circuit for the same time period is called as _________ of an AC quantity.
RMS value
Maximum value
Instantaneous value
Average value
RMS value for an AC quantity can be applied to
Symmetrical waveforms
Unsymmetrical waveforms
Both symmetrical & unsymmetrical waveforms
None of the above
All over the world, sinusoidal voltages and currents are selected for generation of electrical power because:
produce low iron and copper losses
offer less interference to nearby communication lines
produce less disturbance in the network
All the above
A combination of two or more electric cells is called _____
Electric circuit
Battery
Terminals
None of these
An electric bulb has ____ terminals.
3
4
1
2
What is the difference between AC and DC appliances?
AC appliances operate at a constant voltage, while DC appliances fluctuate in voltage.
AC appliances use direct current, while DC appliances use alternating current.
AC appliances are used for batteries, while DC appliances are used for household wiring.
AC appliances use alternating current, while DC appliances use direct current.
How does thermal management play a role in appliance design?
Thermal management ensures safety, efficiency, and performance in appliance design.
Thermal management is only important for aesthetic design.
Thermal management has no impact on energy consumption.
Thermal management is solely focused on reducing noise levels.
What are the key considerations when designing a user interface for an appliance?
Usability, accessibility, intuitive layout, feedback mechanisms, safety, and aesthetic appeal.
Cost of materials
Energy consumption
Brand reputation
Describe the impact of voltage fluctuations on appliance performance.
Voltage fluctuations negatively impact appliance performance by causing overheating, malfunction, and inefficient operation.
Voltage fluctuations improve appliance efficiency.
Voltage fluctuations only affect lighting, not appliances.
Appliances are unaffected by voltage changes.
What is the purpose of a fuse in an electrical appliance?
To increase the voltage in the circuit.
To store electrical energy for later use.
To enhance the performance of the appliance.
The purpose of a fuse in an electrical appliance is to protect it from overcurrent by breaking the circuit.
How do capacitors function in electrical circuits?
Capacitors only allow current to flow in one direction.
Capacitors are used to amplify electrical signals.
Capacitors function by storing and releasing electrical energy in circuits.
Capacitors convert electrical energy into heat.
What are the common types of electrical motors used in appliances?
synchronous motors
AC motors, DC motors, stepper motors, servo motors
induction motors
universal motors
Explain the concept of load calculation in appliance design.
Load calculation is only necessary for large industrial appliances.
Load calculation refers to the physical weight of the appliance.
Load calculation is the process of designing the appliance's exterior appearance.
Load calculation is the process of determining the electrical and thermal loads an appliance will impose during operation.
What is the significance of the power rating on an appliance?
The power rating determines the color of the appliance.
The power rating is used to measure the size of the appliance.
The power rating indicates the weight of the appliance.
The power rating indicates energy consumption and efficiency of the appliance.
How does the design of a circuit affect the performance of an appliance?
The circuit design directly impacts efficiency, reliability, and functionality of the appliance.
Appliance performance is solely determined by its brand.
The circuit design has no effect on the appliance's performance.
The circuit design only affects the aesthetic appearance of the appliance.
What materials are commonly used for electrical insulation?
wood
Rubber, plastic, glass, ceramics, mica
metal
paper
Describe the importance of energy efficiency in appliance design.
Energy efficiency increases appliance weight and size.
Energy efficiency is only relevant for industrial machines.
Energy efficiency in appliance design is important for reducing energy consumption, lowering costs, and minimizing environmental impact.
Energy efficiency has no impact on consumer choices.
What safety standards must electrical appliances meet?
Electrical appliances must only meet ISO standards.
Electrical appliances are exempt from safety standards.
Electrical appliances must be made of metal to be safe.
Electrical appliances must meet safety standards such as UL, CE, and IEC.
Explain the role of resistors in circuit design for appliances.
Resistors are primarily used for wireless communication in circuit design.
Resistors are used to store energy in appliances.
Resistors increase current flow and enhance voltage in circuits.
Resistors control current flow, limit voltage, and protect components in circuit design for appliances.
What is the primary function of a transformer in electrical appliances?
To increase current levels in electrical appliances.
To change voltage levels in electrical appliances.
To store electrical energy for later use.
To convert AC to DC in electrical appliances.
Diagrams of sine waves show two axis. The vertical axis is????
Voltage or amplitude
Time as in period or frequency
Resistance to flow
Tiang bendera sekolah awak
Frequency is 1/period and period is 1/frequency? True or false?
YEA baby
Not until i meet you
Only when the moon is full
