Advertisements
Advertisements
प्रश्न
The following table gives the electrical appliances used, their power and the average time for which they are used each day in a home. Estimate the monthly electricity bill if the rate is 60 paise per unit.
| Sr.no. | Name | Nos. | Power rating | Time/day |
| 1 | Bulb | 4 | 100 W | 7.5 hr |
| 2 | Fans | 2 | 50 W | 10 hr |
| 3 | T.V. | 1 | 100 W | 2 hr |
| 4 | Iron | 1 | 500 W | 1 hr |
| 5 | Electric stove | 1 | 750 W | 2 hr |
Advertisements
उत्तर
We first calculate the total kWh consumption of each appliance per day. This is done is below:
(1) Bulbs: kWh consumption =`(4 xx 100)/1000 "kW" xx 7.5 "h" = 3 "kWh"`
(2) Fans: kWh consumption = `2 xx 50/1000 "kW" xx 10 "h" = 1 "kWh"`
(3) T.V. kWh consumption = `1 xx 100/1000 "kW" xx 2 "h" = 0.2 "kWh"`
(4) Iron: kWh consumption = `1 xx 500/1000 "kW" xx "1 h" = "0.5 kWh"`
(5) Electric stove: kWh consumption = `1 xx 750/1000 "kW" xx "2 h" = "1.5 kWh"`
∴ Total kWh consumption per day = (3 + 1 + 0.2 + 0.5 + 1.5) kWh
= 6.2 kWh = 6.2 unit
∴ No. of.units consumed in one month = 6.2 × 30 unit = 186 units
∴ Monthly electricity bill = 186 × 60 paise = Rs. 111.60.
संबंधित प्रश्न
A current of 2 A is passed through a coil of resistance 75Ω for 2 minutes. (a) How much heat energy is produced? (b) How much charge is passed through the resistance?
An electric bulb is rated at 220 V, 100 W. (a) what is its resistance? (b) what safe current can be passed through it?
Two bulbs are rated 60 W, 220 V and 60 W, 110 V respectively. Calculate the ratio of their
resistances
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
A current passes through a resistor. Let K1 and K2 represent the average kinetic energy of the conduction electrons and the metal ions, respectively.
Write the SI units for:
(a) Electric current
(b) Potential difference
(c) Charge.
Two electric lamps each rating 100 W, 110 V are connected in series to a 220 V power supply and two other electric lamps each of marking 100 W, 220 V are connected in parallel to the same power supply. Will anyone of the two combinations give more light than the other? Give a reason for your answer.
An Electric bulb is marked 100 W, 230 V. What find the energy consumed by the bulb in one hour.
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.
