Advertisements
Advertisements
प्रश्न
An electric iron is rated at 230 V, 750 W. What is its resistance? What maximum current can be passed through it?
Advertisements
उत्तर
V = 230 V, Power = 750 W
P = V × I
∴ 750 = 230 × I
∴ I = 750/230
∴ I = 3.26 A
By Ohm's law `"V"/"I" = "R"`
∴ R = `230/3.26`
∴ R = 70.53 Ω
संबंधित प्रश्न
What is consumed using different electrical appliances, for which electricity bills are paid?
If a bulb of 60W is connected across a source of 220V, find the current drawn by it.
How many joules are there in one kilowatt-hour?
How much energy does a 100 W electric bulb transfer in 1 minute?
(a) 100 J
(b) 600 J
(c) 3600 J
(d) 6000 J
The table below shows the current in three different electrical appliances when connected to the 240 V mains supply:
| Appliance | Current |
| Kettle | 8.5 A |
| Lamp | 0.4 A |
| toaster | 4.8 A |
- Which appliance has the greatest electrical resistance? How does the data show this?
- The lamp is connected to the main supply by using a thin, twin-cored cable consisting of live and natural wires. State two reasons why this cable should not be used for connecting the kettle to the mains supply.
- Calculate the power rating of the kettle when it is operated from the 240 V mains supply.
- A main takes the kettle abroad where the mains supply is 120 V. What is the current is the kettle when it is operated from the 120 V supply?
Why is heating coil wound in the form of a helix in electric stove?
Mention three uses of the carbon arc.
An electric lamp A of 40 W and another electric lamp B of 100 W are connected to 220 V supply. Calculate the ratio of their filament resistances?
An Electric bulb is marked 100 W, 230 V. What current does it take?
The electrical power and current in the circuit relates by ______
