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.
APPEARS IN
संबंधित प्रश्न
An electric bulb is connected to a 220 V power supply line. If the bulb draws a current of 0.5 A, calculate the power of the bulb.
Electrical power P is given by the expression P = (Q × V) ÷ time. What do the symbols Q and V represent?
An electrical appliance having a resistance of 200Ω is operated at 200 V. Calculate the energy consumed by the appliance in 5 minutes (i) in joules (ii) in kWh.
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.
An electric bulb, when connected across a power supply of 220 V, consumes a power of 60 W. If the supply drops to 180 V, what will be the power consumed? If the supply is suddenly increased to 240 V, what will be the power consumed?
Establish the relation that heat produced in a metallic conductor due to the flow of current is V2t/R joules, where V is the potential difference across the ends of the conductor, R its resistance and t is the time in second for which current flows.
Two resistances R1 = 4Ω and R2 = 6Ω are connected in series. The combination is connected with a battery of e.m.f. 6V and negligible resistance. Calculate:
(i) the heat produced per minute in each resistor,
(ii) the power supplied by the battery.
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.
Electric power is inversely proportional to ____________.
What is the meaning of electric power of an electrical device? Write its SI unit.
