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प्रश्न
What is the function of brushes in an electric generator?
What is the function of carbon brushes in d.c. motor?
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उत्तर
Brushes maintain the contact between slip rings (commutator) in an A.C. generator (D.C. generator). So, the current produced in the rotating coil can be tapped out through slip rings (commutator) into the brushes.
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संबंधित प्रश्न
Name the phenomenon which is made use of in an electric generator.
Why are Thermal Power Stations usually located near a river?
Draw the labelled diagram of an A.C. generator. With the help of this diagram, explain the construction and working of an A.C. generator.
Name and state the principle of a simple a.c. generator. What is its use?
In an a.c. generator the speed at which the coil rotates is doubled. How would this affect
- the frequency of output voltage,
- the maximum output voltage is doubled.
State change that you would make to convert an A.C. generator into a D.C. generator. Illustrate the change by a diagram.
The given figures 1 to 3 show the working of a simple A.C. generator. Study the diagrams and answers of the following questions.
(i) State and explain the principle underlying the working of a simple generator.
(ii) Where is the loop of wire placed?
(iii) What happens when the loop is rotated?
(iv) Indicate the direction of the current flow through the wire for the first half of the turn (in first figure). Name and state the rule used in finding the direction of the current.
(v) Indicate the direction of the current for the case shown in second figure.
(vi) Indicate the direction of current in the outer circuit (i.e., electric bulb) in first and third figure.
(vii) What type of current is shown in the above diagrams? Explain.
What causes a continuously alternating EMF in an a.c. generator?
In what direction are the magnetic field arrows drawn between the poles?
How is peak current related to peak EMF and external resistance?
