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प्रश्न
Define an electric current.
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उत्तर १
An electric current is measured by the amount of electric charge moving per unit time at any point in the circuit.
उत्तर २
The magnitude of an electric current is the number of electric charges flowing through a conductor in one second.
संबंधित प्रश्न
One coulomb charge is equivalent to the charge contained in:
(a) 2.6 × 1019 electrons
(b) 6.2 × 1019 electrons
(c) 2.65 × 1018 electrons
(d) 6.25 × 1018 electrons
The atoms of copper contain electrons and the atoms of rubber also contain electrons. Then why does copper conduct electricity but rubber does not conduct electricity?
Which of the following equation shows the correct relationship between electrical unit?
1A = 1C/s or 1c= 1A/s
What is an Ammeter? How is It Connected in a Circuit? Draw a Diagram to Illustrate Your Answer.
Write down the formula which relates electric charge, time and electric current
In the circuit diagram given below five resistances of 10 Ω, 40 Ω, 30 Ω, 20 Ω, and 60 Ω are connected as shown to a 12 V battery.
Calculate:
(a) total resistance in the circuit.
(b) total current flowing in the circuit.
Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs:
(b) for lighting inside the rooms of the hotel?
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?
How do you think the brightness of two lamps arranged in parallel compares with the brightness of two lamps arranged in series (both arrangements having one cell)?
Two lamps, one rated 40 W at 220 V and the other 60 W at 220 V, are connected in parallel to the electric supply at 220 V.
(a) Draw a circuit diagram to show the connections.
(b) Calculate the current drawn from the electric supply.
(c) Calculate the total energy consumed by the two lamps together when they operate for one hour.
How does the heat H produced by a current passing through a fixed resistance wire depend on magnitude of current I?
A switch must be connected in:
(a) Live wire (b) neutral wire
(c) earth wire (d) either earth or neutral wire
Two resistors of 2.0 Ω and 3.0 Ω are connected (a) in series (b) in parallel, with a battery of 6.0 V and negligible internal resistance. For each case draw a circuit diagram and calculate the current through the battery.
Calculate the amount of energy transferred by a 10 A electric current flowing through a resistor of 5 o for 15 minutes.
A charge of 80 C flows in a conductor for 2 minutes.
(a) Calculate the current flowing through the conductor.
(b) If the current through a heater is 4 A what charge must be passing in 8 seconds?
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 ........ .......... ............ .............. |
The following appliances are to be used on 240 V supply. Calculate the current used by each and say which fuse, 2 amp, 5 amp or 13 amp should be incorporated with each, (i) A television rated at 150 W, (ii) An electric iron rated at 750 W, (iii) An immersion heater rated at 3000 W, (iv) A hair dryer rated at 500 W. How much will it cost to run the television set for 100 days for an average of 4 hours a day at 60 paise per unit?
Tick (✓) the correct choice among the following :
Which of the following changes would enable a millimeter to be used as a
direct current ammeter reading upto 1 A?
1 kWh = `(1 "volt" xx 1 "ampere" xx "_________")/1000`
Answer the following question.
What is the function of a galvanometer in a circuit?
Explain, why the potential difference across the terminals of a cell is more when the cell is not in use than it is when the cell is being used.
What is meant by internal resistance of a cell?
- What is meant by electric current?
- Name and define its unit.
- Which instrument is used to measure the electric current? How should it be connected in a circuit?
When an electric current is passed, electrons move from:
A current of 2A passing through the conductor produces 80 J of heat in 10 seconds. The resistance of the conductor is ______.
