Advertisements
Advertisements
प्रश्न
Express watt hour and kilowatt hour in joule.
Advertisements
उत्तर
1 kWh = 1W × 1 hour = 1000 W × (60 × 60) s
= 1W × 1s × 105 × 36 = 36 × 105 J = 3.6 × 106 J
संबंधित प्रश्न
What is the meaning of the symbol kWh? Which quantity does it represent?
An electric kettle for use on a 230 V supply is rated 3000 W. For safe working, the cable connected to it should be able to carry at least:
(a) 2 A
(b) 5 A
(c) 10 A
(d) 15 A
Two bulbs are rated 60 W, 220 V and 60 W, 110 V respectively. Calculate the ratio of their
resistances
Two resistors A and B of resistance 4 Ω and 6 Ω respectively are connected in parallel. The combination is connected across a 6 volt battery of negligible resistance. Calculate: (i) the power supplied by the battery, (ii) the power dissipated in each resistor.
Calculate the resistance of an electric bulb which allows a 10 A current when connected to a 220 V power source.
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?
How is the amount of heat produced calculated due to the passage of current in a metallic conductor? Derive an expression for it.
Find the cost of operating an electric toaster for two hours if it draws 8 A current on a 110 volt circuit. The cost of electrical energy is Rs. 2.50 per kWh.
What is the commercial unit of electrical energy?
