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प्रश्न
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उत्तर
A switch is an on-off device for current in a circuit (or in an appliance). Its main function is either to connect or to disconnect an electrical appliance in an electric circuit.
Switches are always connected in the live wire of circuits so that when a switch is in 'off' position, no current flows through the appliance and its live and neutral wires are at same potential and it is safe to touch the live wire leading to the appliance, even when the fuse is blown.
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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
If the charge on an electron is 1.6 × 10−19 coulombs, how many electrons should pass through a conductor in 1 second to constitute 1 ampere current?
If a charge of 420 C flows through a conducting wire in 5 minutes what is the value of the current?
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.
A wire is passed through a piece of cardboard as shown in fig .. An electric current flows vertically down the wire and then flows back up. The two sections of the write are observed to repel each other.
(a) Wi th the aid of a diagram, describe how you would plot the magnetic field lines on the card .
(b) Sketch the magnetic field patterns around both the sections of the wire. Use your sketch to explain why the two sections repel each other.
(c) The repulsive force between the two sections is small. What changes could be made to increase it?
State the S.I. units of electrical power.
An electric kettle is rated 2.5 kW, 250 V. Find the cost of running the kettle for two hours at Rs. 5.40 per unit.
A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly
