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प्रश्न
At what frequency is AC supplied to residential houses?
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उत्तर
The residential A.C. supply frequency is \[50\ \text{Hz}\].
संबंधित प्रश्न
The commercial unit of energy is :
(a) watt
(b) watt-hour
(c) kilowatt-hour
(d) kilo-joule
A geyser is rated 1500 W, 250 V. This geyer is connected to 250 V mains. Calculate:
(i) the current drawn
(ii) the energy consumed in 50 hours, and
(iii) the cost of energy consumed at Rs. 4.20 per kWh
Write the SI units for:
(a) Electric current
(b) Potential difference
(c) Charge.
State the position of heating element with respect to principal focus of concave reflector and give reason for choosing this position.
An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the resistance of its filament while glowing.
A bulb is marked 100W, 220V and an electric heater is marked 2000 W, 220 V.
(i) What is the ratio between the resistances of these two devices?
(ii) How does the power-voltage rating of a device help us to decide about the type of leads (connecting wires) to be used for it?
(iii) In which of the above two devices, a thicker connecting wire of lead is required?
If a heater coil rated lkW, 220 V is connected in series with an electric bulb of 100 W, 220 V and are supplied 200V, power consumed by the bulb in this circuit is ______.
A room has AC run for 5 hours a day at a voltage of 220V. The wiring of the room consists of Cu of 1 mm radius and a length of 10 m. Power consumption per day is 10 commercial units. What fraction of it goes in the joule heating in wires? What would happen if the wiring is made of aluminium of the same dimensions?
`[ρ_(Cu) = 1.7 xx 10_(Ωm)^-8, ρ_(Al) = 2.7 xx 10^-8 Ωm]`
