Advertisements
Advertisements
प्रश्न
An electrical appliance is rated 1500 W, 250 V. This appliance is connected to 250 V mains. Calculate:
(i) the current drawn,
(ii) the electrical energy consumed in 60 hours,
(iii) the cost of electrical energy consumed at Rs. 2.50 per kWh.
Advertisements
उत्तर
(i) Since, W = V × i, But given that W = 1500, V = 250
Current, i = `"W"/"n"`
`= 1500/250 = 6` amperes
(ii) Energy consumed in 60 hours
`= ("Watts" xx "hours")/1000` kWh
`= (1500 xx 60)/1000 = 90` kWh
(iii) Cost of 90 kWh at Rs. 2.50/kWh = Rs. 90 × 2.50 = Rs. 225.00.
संबंधित प्रश्न
State two factors on which the electrical energy consumed by an electrical appliance depends.
Write the SI units for:
(a) Electric current
(b) Potential difference
(c) Charge.
Define electric power. An electrical device of resistance R is connected across a source of voltage V and draws a current I. Derive an expression for power in terms of current and resistance.
A device is used to transform 12 V a.c. to 200 V a.c. What is the name of this device? Name the principle on which it works.
What would happen and why, to an electric bulb when it is connected across a supply of voltage (i) lower (ii) higher than its proper rating?
An Electric bulb is marked 100 W, 230 V. What current does it take?
A bulb is connected to a battery of e.m.f. 6V and internal resistance 2Ω A steady current of 0.5A flows through the bulb. Calculate the heat energy dissipated in the bulb in 10 minutes.
A battery of e.m.f. 12V and internal resistance 1.6 Ω is connected to two resistors of 4Ω and 6Ω connected in parallel. Calculate:
(i) the current drawn from the battery,
(ii) the power dissipated in each resistor,
(ii)the total power supplied by the battery.
What is the commercial unit of electrical energy?
Using a long extension cord in which each conductor has a resistance of 8Ω, a bulb marked as '100 W, 200 V' is connected to a 220 V dc supply of negligible internal resistance as shown in the figure. The power delivered to the bulb is ______ W.
