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प्रश्न
State one advantage of using a.c. over d.c.
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उत्तर
The voltage of a.c. can be stepped up by the use of step-up transformer at the power generating station before transmitting it over long distances. It reduces the loss of electrical energy as heat in the transmission line wires. On the other hand, if d.c. is generated at the power generating station, its voltage cannot be increased for transmission, and so due to passage of high current in the transmission line wires, there will be a huge loss of electrical energy as heat in the line wires.
संबंधित प्रश्न
The essential difference between an AC generator and a DC generator is that
Name the device which converts mechanical energy into electric energy.
An electric generator converts:
(a) electrical energy into mechanical energy.
(b) mechanical energy into heat energy.
(c) electrical energy into chemical energy.
(d) mechanical energy into electrical energy.
The frequency of alternating current (a.c.) supply in India is:
(a) 0 Hz
(b) 50 Hz
(c) 60 Hz
(d) 100 Hz
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.
An a.c. generator changes the ______energy to ______ energy.
A flat coil of wire rotates at a constant speed about an axis perpendicular to a uniform magnetic field. Draw a graph to show how the induced e.m.f. varies relative to the positions of the coil during its one complete rotation. At what position of the coil, the e.m.f. has the maximum value?
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.
State true or false:
The frequency of AC is 50 Hz.
A device for producing electric current is ______.
