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प्रश्न
State a relation between electrical power, resistance and potential difference in an electrical circuit.
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उत्तर
In an electrical circuit, electrical power
P = V2/R
where V = potential difference and R = resistance.
संबंधित प्रश्न
When a 4 Ω resistor is connected across the terminals of a 12 V battery, the number of coulombs passing through the resistor per second is:
(a) 0.3
(b) 3
(c) 4
(d) 12
Give one example to show how the resistance depends on the nature of material of the conductor.
The diagram below shows part of a circuit:
If this arrangement of three resistors was to be replaced by a single resistor, its resistance should be:
(a) 9 Ω
(b) 4 Ω
(c) 6 Ω
(d) 18 Ω
When do you say that the resistors are connected in this way? Draw a circuit diagram.
Name the material of wire used for making standard resistances. Give a reason.
Write an expression for the resistance of a conducting wire in terms of its length and area of cross-section.
Define the term resistivity and state its S.I. unit. Which will have higher resistivity a conductor or an insulator.
Two lamps of resistance 30Ω and 20Ω respectively are connected in series in a 110V circuit. Calculate:
(i) the total resistance in the circuit
(ii) the current in the circuit, and
(iii) the voltage drop across each lamp.
Two electric bulbs have resistances in the ratio 1 : 2. If they are joined in series, the energy consumed in them is in the ratio:
