Copper and carbon wires are connected in series and the combined resistor is kept at 0⁰C. Assuming the combined resistance does not vary with temperature, the ratio of the resistances of carbon and copper wires […]
The temperature coefficient of the resistance of a wire is 0.00125 per ⁰C. At 300 K its resistance is 1Ω. The resistance of wire will be 2Ω at
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(a) 1154K (b) 1100K […]
The electron drift speed is small and the change of the electron is also small but still, we obtain large current in a conductor. This is due
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(a) the conducting property of […]
A silver wire of radius 0.1 cm carries a current of 2A. If the charge density in silver is 5.86×10²⁸ m⁻³, then the drift velocity is
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(a) 0.2×10⁻³ ms⁻¹ (b) 0.4×10⁻⁴ ms⁻¹ […]
An electron revolves in a circle at the rate of 10¹⁹ rounds per second. The equivalent current is (e=1.6×10⁻¹⁹C)
Options
(a) 1.0A (b) 0.2A (c) 0.1A (d) 2.0A
Correct Answer:
0.2A
Explanation:
Current I […]
When a wire of uniform cross-section a, length l and resistance R is bent into a complete circle, resistance between any two of diametrically opposite points will be
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(a) R/4 (b) 4R […]
The resistances of the four arms P,Q,R and S in a Wheatstone’s bridge are 10Ω, 30Ω, 30Ωand 90Ω respectively. The emf and internal resistance of the cell are 7V and 5Ω, respectively. If the galvanometer […]
When 4 A current flows for 2 min in an electroplating experiment, then m gram of silver is deposited. Then the amount (in gram) of silver deposited by 6 A current flowing for 40 s […]
In India, electricity is supplied for domestic use at 200V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of […]
In a potentiometer experiment, the balancing with a cell is at length 240 cm. On shunting the cell with a resistance of 2Ω , the balancing becomes 120 cm. The internal resistance of the cell […]
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