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प्रश्न
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उत्तर
Features which provide greater efficiency to a transformer are:
(i) The core of the transformer is laminated which prevents the formation of eddy currents.
(ii) A closed soft-iron core is used which reduces the magnetic field link loss and hysteresis loss.
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संबंधित प्रश्न
A current of 4 A flows around a circuit for 10 s. How much charge flows past a point in the circuit in this time?
Consider the circuit given below:
(a) In which circuit are the lamps dimmest?
(b) In which circuit or circuits are the lamps of equal brightness to the lamps in circuit (i)?
(c) Which circuit gives out the maximum light?
The following circuit diagram shows three resistors 2 Ω, 4 Ω and R Ω connected to a battery of e.m.f 2V and internal resistance 3 Ω. If the main current of 0.25 A flows through the circuit, find:
- the p.d. across the 4 Ω resistors,
- the p.d. across the internal resistance of the cell,
- the p.d. across the R Ω or 2 Ω resistors, and
- the value of R.
Complete the following sentence:
Fuse wire has a ............ Melting point and it is made of an alloy of ......... and if the current in a circuit rises too high, the fuse wire ...........
Two cells each having an e.m.f. of 2 V and an internal resistance of 2Ω are
connected (a) In series, and ( b) In para 1le l as shown in fig. . What is the
current flowing through the cir cu it in each_ case?
An electric bulb is marked '100 W, 250 V'. What information does this convey?
A bulb is connected to a battery of p.d. 4 V and internal resistance 2.5 Ω . A steady current of 0.5 A flows through the circuit. Calculate:
The resistance of the bulb
Match the following:
| 1. | 1 mA | a. | series |
| 2. | 1 pA | b. | ohmmeter |
| 3. | Ammeter | c. | 10-6 ampere |
| 4. | Electrical resistivity | d. | 10-3 ampere |
