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प्रश्न
What is the Flow of Charge Called?
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उत्तर
The flow of electric charge in a conductor is called electric current. If a charge of Qcoulombs flows through a conductor in time t seconds, the magnitude of electric current is given by, I = Q/t.
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संबंधित प्रश्न
If the amount of electric charge passing through a conductor in 10 minutes is 300 C, the current flowing is:
(a) 30 A
(b) 0.3 A
(c) 0.5 A
(d) 5 A
A battery and three lamps are connected as shown:
Which of the following statements about the currents at X, Y and Z is correct?
(a) The current at Z is greater than that at Y.
(b) The current at Y is greater than that at Z.
(c) The current at X equals the current at Y.
(d) The current at X equals the current at Z.
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.
(d) Which circuit would have less current in it?
An electrician has wired a house in such a way that if a lamp gets fused in one room of the house, all the lamps in other rooms of the house stop working. What is the defect in the wiring?
Draw a circuit diagram showing two electric lamps connected in parallel together with a cell and a switch that works both lamps. Mark an â’¶ on your diagram to show where an ammeter should be placed to measure the current.
A given wire of resistance 1 Ω is stretched to double its length. What will be its new resistance?
State two differences between the e.m.f and terminal voltage of a cell.
A wire of uniform thickness with a resistance of 27Ω is cut into three equal pieces and they are joined in parallel. Find the equivalent resistance of the parallel combination.
Define the following:
Semiconductors
If the potential differences between two parts of a thundercloud is 10s V,
what is the amount of energy given up during the passage of 20 coulombs?
(a)2x10-7J
(b)200J
(c)Sx106 j
(d)2x 109J
(e)2x 1010 J
A bulb marked 12 V, 24 W operates on a 12 V battery for 20 minutes. Calculate:
- The current flowing through it, and
- The energy consumed.
An electric bulb is rated 250 W, 230 V.
- the energy consumed in one hour, and
- the time in which the bulb will consume 1.0 kWh energy when connected to 230 V mains.
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate :
The total current taken from the supply
Fill in the blank :
1 mA = ............................. A.
Three resistances, of which two are equal when connected in series have an effective resistance of 30 ohms. When the three resistances are connected in parallel, the effective resistances is 3 ohms. Find the values of the individual resistances.
Match the items in column-I to the items in column-II:
| Column - I | Column - II | ||
| (i) | electric current | (a) | volt |
| (ii) | potential difference | (b) | ohm meter |
| (iii) | specific resistance | (c) | watt |
| (iv) | electrical power | (d) | joule |
| (v) | electrical energy | (e) | ampere |
Conventionally, the direction of the current is taken as:
