UN S
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1) on what factors does the resistance of a conductor depend?
2) will current flow more easily through a thick wire or a thin wire of the
same material, when connected to the same source? Why?
3) Let the resistance of an electrical component remains constant while
.the potential difference across the two ends of the component decreases
to half of its former value. What change will occur in the current through
it?
4) Why are coils of electric toasters and electrie irons made of an alloy
rather than a pure metal?
5) Use the data in Table 12.2 to answer the following -
(a) Which among iron and mercury is a better conductor?
(b) Which material is the best conductor?
a) RESISTANCE OF A SYSTEM OF RESISTORS
b) hout some simple electric circuits. We
Answers
Answer:
1.The resistance of a conductor depends on the cross sectional area of the conductor, the length of the conductor, and its resistivity.
2.The current will flow more easily through the thick wire than the thin wire. It is because the resistance of a conductor is inversely proportional to its area of cross-section. If thicker the wire, less is resistance and hence more easily the current flows.
3.Therefore, the amount of current flowing through the electrical component is reduced by half.
4.The resistivity of an alloy is higher than the pure metal.
At high temperatures, the alloys do not oxidize.
Alloy does not melt readily and get deformed.
Alloys have a low-temperature coefficient of resistance.
5(a)Iron is the better conductor of electricity than mercury as its Resistance is less than mercury's, and resistance is inversely proportional to current.