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प्रश्न
Copy the given diagram of a transformer and complete it. Name the parts A and B. Name the part you have drawn to complete the diagram. What is the material of this part? Is this transformer a step-up or step-down? Give reason.
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उत्तर
The completed diagram is given below:
Part A is called primary coil. Part B is called a secondary coil.
The part drawn is called core.
The material of the core is soft iron.
(i) This transformer is step-down since it has more turns in the primary coil than in secondary coil.
(ii) A step-up transformer has more turns in secondary coil as compared to that in the primary coil, while a step-down transformer has more turns in primary coil as compared to that in secondary coil.
(iii) In a step-up transformer the wire in the primary coil is thicker as compared to that in secondary coil, while in a step-down transformer the wire in secondary coil is thicker as compared to that in primary coil.
संबंधित प्रश्न
Complete the following sentence :
……… energy is converted into …………energy by an electric motor.
The following diagram in Fig. 10.44 shows a coil X connected to a sensitive centre –zero galvanometer G and a coil P connected to a battery through a switch S.
(a) Describe the observation when the switch S is (i) closed suddenly, (ii) then kept closed, (iii) finally opened.
(b) Name and state the law which explains the above observations.
The primary coil of a transformed has 800 urns and the secondary coil has 8 turns. It is connected to a 220 V a.c. supply. What will be the output voltage?
Describe, with the help of a suitable diagram, the working principle of a step-up transformer. Obtain the relation between input and output voltages in terms of the number of turns of primary and secondary windings and the currents in the input and output circuits.
A transformer lowers e.m.f. 220 V to 12 volts. If the number of turns in primary are 8800, how many turns are in secondary coil?
A 200V/120V step-down transformer of 90% efficiency is connected to an induction stove of resistance 40 Ω. Find the current drawn by the primary of the transformer.
Assertion: A transfonner cannot work on D.C. supply.
Reason: D.C. changes neither in magnitude nor in direction.
What type of transformer is used in a mobile phone charger?
