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प्रश्न
What is an electric current?
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उत्तर
An electric current is the flow of electric charge called electrons in a conductor and its magnitude is the amount of electric charge passing through a given point of the conductor in one second.
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संबंधित प्रश्न
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
In which of the following cases more electrical energy is consumed per hour?
(i) A current of 1 ampere passed through a resistance of 300 ohms.
(ii) A current of 2 amperes passed through a resistance of 100 ohms.
How does the heat H produced by a current passing through a fixed resistance wire depend on magnitude of current I?
A given wire of resistance 1 Ω is stretched to double its length. What will be its new resistance?
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.
A battery of e.m.f. 15 V and internal resistance 3 ohm is connected to two resistors of resistance 3 ohm and 6 ohm in series. Find:
(i) The current through the battery,
(ii) The p.d. between the terminals of the battery.
What would be the danger involved in replacing a blown fuse with the one which would carry a large current?
An electric kettle has a heating element which is rated at 2 kW when connected to a 250 V electric supply. Calculate the
(a) Current which flows in the element when it is connected to a 250 V supply,
(b) Resistance of the filament,
(c) Heat produced in 1 minute by the element,
(d) Cost of running the kettle for 10 minutes a day for 30 days of the month, at the rate of Rs. 3.00 per unit.
In a house there are 6 bulbs of 100 W each used for 4 hours a day, 4 bulbs of 60 W each used for 8 hours a day, an immersion heater of 2.5 kW used for 1 hour per day, and an electric iron of 800 W used for 2 hours per day. Calculate the cost of monthly electric bill for the month of April at the rate of 80 p per unit.
An electric oven is rated as 1.5 kW, 250 V. If it is connected to a 250 V mains, calculate the
(a) Current drawn,
(b) Energy consumed in 20 hours,
(c) Cost of energy consumed in 20 hours at the rate of Re. 1 per unit.
Name the principle on which a transformer works.
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?
An electrical gadget can give an electric shock to its user under certain circumstances. Mention any two of these circumstances.
Name any two devices, which are working on the heating effect of the electric current.
Define the following:
Conventional current
