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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 device used for producing electric current is called a ______.
State whether the following statement is true or false.
An electric motor converts mechanical energy into electrical energy.
Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes?
Explain the principle of an electric generator.
State two ways in the which the current alternating current and direct current?
State whether the following statement are true of false:
A wire with a green insulation is usually the live wire.
The current induced in a closed circuit only if there is ______.
What determines the frequency of a.c. produced in a generator?
An a.c. generator changes the ______energy to ______ energy.
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.
