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प्रश्न
Two wires of same material and same lengths have radii in the ratio of 2 : 3, Compare their resistances.
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उत्तर
Given: r1 : r2 = 2 : 3
Area of cross-section of wire = a = π r2
∴ a1 : a2 = `"r"_1^2 : "r"_2^2 = 4 : 9`
Resistance of wire R α `1/"a"`
∴ `"R"_1/"R"_2 = "a"_2/"a"_1 = 9/4`
संबंधित प्रश्न
In series combination which remains constant?
(a) Voltage
(b) Current
(c) Both current and voltage
(d) Both are variables
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2Ω resistor A, 1Ω resistor B and 4Ω resistor C are connected in parallel. The combination is connected across a 2V battery of negligible resistance. Draw the diagram of the arrangement and calculate:
(i) The current in each resistor A and C,
(ii) The current through battery.
