A. Increasing the cross-section area of the arc
B. Splitting the arc in number of arcs in parallel
C. Shortening the arc
D. Splitting the arc in number of arcs in series
Answer
D. Splitting the arc in number of arcs in series
Explanation
Resistance of arc may be increased by
1. Lengthimg the arc:
As the length of the arc increases, the arc resistance also increases. The length of the arc can be increased by increasing the gap between contacts.
2. Cooling of arc:
Cooling help in de-ionisation of the medium between the contacts. This increases the arc resistance and removes the heat from the arc.
3. Reducing cross-sectional area of arc:
By reducing the cross-section area of the arc the voltage necessary to maintain the arc is increased. This can be done by allowing the arc to pass through a similar area compared to a wide area.
4. Splitting of Arc:
The resistance of the arc can be increased by splitting the arc into a number arc in series. These may be split by introducing some conducting plates between the contacts of the circuit breaker.
The major disadvantage in this method is that is very high energy is dissipated in the arc. Therefore, it is employed only in dc circuit breakers and low capacity is ac circuit breaker.
Power System MCQs With Explanation
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What is the function of economizer in Thermal Power Plant
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When earth fault occurs
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In a transformer the primary flux is
The noise of the transformer is mainly due to
Buchholz relay is used for the protection
Iron loss in a transformer can be determined by
Oil is provided in an oil-filled transformer for
In a star-delta transformer, the delta side phase voltage leads the star sides phase voltage by an angle
Minimum voltage regulation occurs in transformer when the power factor of the load is
The chemical used in the breather of a transformer should have the property of
The power transformer can be termed as a constant
In a transformer, which of the following losses are zero?
Which of the following Transformer can have a tap changer?
If the supply frequency (f) of a transformer decreases, the effect of frequency on the transformer's secondary output voltage?
The primary winding of a transformer has a 120 V ac supply. What is the value of secondary voltage if the turn ratio is 10?
The efficiency of a power transformer is _____ at full load.
In a transformer the relation between the input frequency and the output voltage on secondary winding is _____.
In a current transformer, _____ winding is closed.
A transformer is a _____ device.
A step-down transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
A step-up transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
Transformer works on ______ principle.
Shell Type Transformer is mainly used for
A Magnetic Oil level Guage (MOG) is used in the Transformer to
The Function Of Power Transformer is/are
The Radiators are used in transformers for
The noise of the transformer is mainly due to
Buchholz relay is used for the protection
Iron loss in a transformer can be determined by
Oil is provided in an oil-filled transformer for
In a star-delta transformer, the delta side phase voltage leads the star sides phase voltage by an angle
Minimum voltage regulation occurs in transformer when the power factor of the load is
The chemical used in the breather of a transformer should have the property of
The power transformer can be termed as a constant
In a transformer, which of the following losses are zero?
Which of the following Transformer can have a tap changer?
If the supply frequency (f) of a transformer decreases, the effect of frequency on the transformer's secondary output voltage?
The primary winding of a transformer has a 120 V ac supply. What is the value of secondary voltage if the turn ratio is 10?
The efficiency of a power transformer is _____ at full load.
In a transformer the relation between the input frequency and the output voltage on secondary winding is _____.
In a current transformer, _____ winding is closed.
A transformer is a _____ device.
A step-down transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
A step-up transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
Transformer works on ______ principle.
Shell Type Transformer is mainly used for
A Magnetic Oil level Guage (MOG) is used in the Transformer to
The Function Of Power Transformer is/are
The Radiators are used in transformers for
Synchronous Motor MCQs With Explanation
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The negative phase sequence in a three-phase synchronous motor exists when the motor is
What happens if the field winding of the synchronous motor is short-circuited?
For power factor correction, synchronous motors operate at
Induction Motor MCQs With Explanation
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