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प्रश्न
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.
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उत्तर
Given ,
Power of kettle , P = 2.5 kW
Voltage , V = 250 V
Time, t = 2 h
As , Energy , E = P × t
= 2.5 × 2 = 5 kWh
Cost per unit of energy = Rs 5.40
Cost for 5 kWh of energy = 5.40 × 5 = Rs 27
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संबंधित प्रश्न
What does an electric circuit mean?
What is the current in a circuit if the charge passing each point is 20 C in 40 s?
An electric circuit consisting of a 0.5 m long nichrome wire XY, an ammeter, a voltmeter, four cells of 1.5 V each and a plug key was set up.
(i) Draw a diagram of this electric circuit to study the relation between the potential difference maintained between the points 'X' and 'Y' and the electric current flowing through XY.
A p.d. of 6 V is applied to two resistors of 3 Ω and 6 Ω connected in parallel. Calculate:
(a) the combined resistance
(b) the current flowing in the main circuit
(c) the current flowing in the 3 Ω resistor.
Using the circuit given below, state which of the following statement is correct?
(a) When S1 and S2 are closed, lamps A and B are lit.22
(b) With S1 open and S2 closed, A is lit and B is not lit.
(c) With S2 open and S1 closed A and B are lit.
(d) With S1 closed and S2 open, lamp A remains lit even if lamp B gets fused.
A 720 W heater operates from a 220 V line voltage. Calculate:
(a) The electrical energy consumed by the heater in 3 h.
(b) The cost of electrical energy consumption at the rate of 60 paise per kWh.
The circuit diagram (Fig.) shows a battery of e.m.f. 6 volts and internal
resistance of 0.8 Ω oonnected in series. Find the
(a) Current reoorded by the ammeter,
(b) P.d. across the terminals of the resistor B,
( c) Current passing through each of the resistors B, C and D, and
( d) P.d. across the terminals of the battery.
Problems for practice:
If 3A current flows through a circuit, then convert the current in terms of a milliampere.
A switch in an electric circuit is used to:
