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प्रश्न
How does the presence of impurities in a metal affect its resistance?
उत्तर
The presence of impurities in a metal increases its resistivity (also resistance) and it does not undergo oxidation easily even at a high temperature.
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संबंधित प्रश्न
Find the expression for resistors connected in series.
Give one example to show how the resistance depends on the nature of material of the conductor.
A p.d. of 4 V is applied to two resistors of 6 Ω and 2 Ω connected in series. Calculate:
(a) the combined resistance
(b) the current flowing
(c) the p.d. across the 6 Ω resistor
Draw a V-I graph for a conductor at two different temperatures. What conclusion do you draw from your graph for the variation of resistance of conductor with temperature?
State how are the two resistors joined with a battery when equivalent resistance is more than either of the two resistances.
When do you say that the resistors are connected in this way? Draw a circuit diagram.
Write an expression for the resistance of a conducting wire in terms of its length and area of cross-section.
How does the resistivity of a semiconductor depend on temperature?
Six equal resistors of 1 ohm each are connected to form the sides of a hexagon ABCDEF. Calculate the resistance offered by the combination if the current enters at A and leaves it at D.
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:
