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प्रश्न
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उत्तर
Given, P = 1.5 kW= 1500 W, p.d. = 220 V
We know that,
P=VI
I = `"P"/"V" = 1500/220` = 6.8 A
Thus a fuse of rating 7A may be used with the appliance and it should be connected in the live wire before connectimg it to the appliance.
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संबंधित प्रश्न
Define the unit of current.
Fill in the folloing blank with suitable words:
A current is a flow of ............... .For this to happen there must be a ............... circuit.
In 10 s, charge of 25 C leaves a battery, and 200 J of energy are delivered to an outside circuit a result.
What current flows from the battery?
Which statement/statement is/are correct?
1. An ammeter is connected in series in a circuit and a voltmeter is connected in parallel.
2. An ammeter has a high resistance.
3. A voltmeter has a low resistance.
(a) 1, 2, 3
(b) 1, 2
(c) 2, 3
(d) 1
Ten bulbs are connected in a series circuit to a power supply line. Ten identical bulbs are connected in a parallel circuit to an identical power supply line.
- Which circuit would have the highest voltage across each bulb?
- In which circuit would the bulbs be brighter?
- In which circuit, if one bulb blows out, all others will stop glowing?
- Which circuit would have less current in it?
A bulb marked 12 V, 24 W operates on a 12 volt car battery for 20 minutes. Calculate:
(i) The current flowing through it, and
(ii) The energy liberated.
Define the following:
Super conductors
Complete the following table. The first answer has been given as an example
| Quantity | Unit |
|
(a) Electrical potential Volt ( b) Resistance ( c) Power ( d) Energy ( e) Resistivity |
Volt ........ .......... ............ .............. |
Fig. shows a 3 pin plug with the cover removed. The electric cable
connected to the plug contains 3 wires with colour coded insulation namely brown, blue and green.

- Identify each of the colour coded wires by stating to which of the
terminals A, B or C in the diagram they should be connected. - Identify the terminal through which no current passes in normal
circumstances. - What is the purpose of the earthed wire connected to an electric
appliance like an electric heater? Describe how it works.
Answer the following question.
An electric lamp of resistance 20 Ω and a conductor of resistance 4 0 are connected to a 6 V battery as shown in the circuit. Calculate: 
(a) the total resistance of the circuit,
(b) the current through the circuit,
(c) the potential difference across the (i) electric lamp and (ii) conductor, and
(d) power of the lamp.
