What is meant by "electrical resistance" of a conductor ? State how resistance of a conductor is affected when $(i)$ a low current passes through it for a short duration; $(ii)$ a heavy current passes through it for about $30$ seconds.
What is meant by "electrical resistance" of a conductor ? State how resistance of a conductor is affected when $(i)$ a low current passes through it for a short duration; $(ii)$ a heavy current passes through it for about $30$ seconds.
It is the opposition offered to the flow of current by a conductor.
$(i)$ No effect on resistance, low current, hence no appreciable rise in temperatue-so no change in resistivity.
$(ii)$ Heavy current for about $30$ seconds may increase the temperature of the conductor appreciably$-$so resistivity will change$/$ increase.
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