be equal to the phasor sum of the unbalanced currents
The correct answer is that in an unbalanced three-phase system, the neutral current will be equal to the phasor sum of the unbalanced currents.
In a balanced three-phase system, the phasor sum of the three line currents is zero, resulting in zero neutral current. However, in an unbalanced system, the line currents are unequal in magnitude and/or phase angle. This imbalance causes a net current to flow through the neutral conductor.
Let's denote the three phase currents as \(I_a\), \(I_b\), and \(I_c\). In a four-wire system (with a neutral wire), the neutral current \(I_n\) is the sum of these three phase currents:
\(I_n = I_a + I_b + I_c\)
Since the system is unbalanced, \(I_a\), \(I_b\), and \(I_c\) are not equal in magnitude and/or phase angle. Therefore, their phasor sum will be non-zero, resulting in a non-zero neutral current. The other options are incorrect because they don't account for the fundamental principle of current summation in a neutral wire for an unbalanced three-phase system.
Similar Questions
A three phase circuit is connected with balanced delta connected load of impedance 100 Ω. If the current in each phase is 5 A, the voltage across each load will be
- In a balanced 3 phase circuit, neutral current is always ________.
Which of the following is true when there is an unbalanced star connected load in a three-phase system?
Which of the following statements about a star connected three phase system is correct?
Which of the following is a possible cause of an unbalanced load in a three-phase system?
Which of the following is true for a system with an unbalanced load of a three-phase system?
- If the load on a three-phase system is unbalanced, the power calculation becomes more complex because
- In a balanced three-phase system, the phase angles between the line-to-line voltages are
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Important Questions from Three Phase Circuits
In a balanced three-phase, star-connected system, the phase difference between phase voltages and their respective line voltages is:
Three equal impedances are first connected in star across a balanced 3 phase supply. If connected in delta across the same supply
The power taken by a 3-ϕ load is given by the expression
A three phase circuit is connected with balanced delta connected load of impedance 100 Ω. If the current in each phase is 5 A, the voltage across each load will be
A load of three impedances each (6 + j9) is supplied through a line having an impedance of (1 + j2) Ω. The supply voltage is 400 V at 50 Hz. Determine input and output powers respectively when the load is star connected.
