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; $(ii)$ 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; $(ii)$ heavy current passes through it for about $30$ seconds.
Electrical resistance is the opposition offered to the flow of current by the conductor.
$(i)$ The resistance will remain the same as a low current passes through it for a short duration.
$(ii)$ The resistance will increase when a heavy current passes through it for about $30$ min. This is because resistance depends directly on the temperature of the conductor, and heavy current will heat up the conductor.
Similar Questions
$(a)$ Resistivity of iron is $10 \times 10^{-8} \;\Omega m$ and of mercury is $94 \times 10^{-8}\; \Omega m$. Which among iron and mercury is a better conductor ? Give reason.
$(b)$ Resistivity of a material $A$ is in the range of $10^{10}-10^{\text {14 }} \;\Omega m$ while that of $B$ is in the range of $10^{-6}-10^{-8} \;\Omega$ m. Which of the two will behave as an insulator and why?
$(a)$ Resistivity of iron is $10 \times 10^{-8} \;\Omega m$ and of mercury is $94 \times 10^{-8}\; \Omega m$. Which among iron and mercury is a better conductor ? Give reason.
$(b)$ Resistivity of a material $A$ is in the range of $10^{10}-10^{\text {14 }} \;\Omega m$ while that of $B$ is in the range of $10^{-6}-10^{-8} \;\Omega$ m. Which of the two will behave as an insulator and why?
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How can we measure the potential difference across the ends of a conductor ?
Name and define $SI$ unit of resistance. Calculate the resistance of a resistor if the current flowing through it is $200\, mA$, when the applied potential difference is $0.8\, V$.
Name and define $SI$ unit of resistance. Calculate the resistance of a resistor if the current flowing through it is $200\, mA$, when the applied potential difference is $0.8\, V$.
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