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प्रश्न
Why does the filament of an electric bulb in an electric circuit get white-hot, but not the connecting wires?
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उत्तर
The filament of an electric bulb is made up of tungsten having high resistance. Due to its high resistance, on passing an electric current through it, electrical energy changes into heat energy. So much heat is produced that filament of bulb becomes white-hot and gives light.
The resistance of connecting wires is very low and hence the connecting wires do not get heated.
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संबंधित प्रश्न
The unit of current is :
State and define the S.I. unit of resistance.
State the unit of electric potential and define it.
How is potential difference related to work done and quantity of charge?
What do you understand by the term series circuit?
State two characteristics of resistance in the parallel circuit.
The following figure shows a metal rod PQ mounted on an insulated stand. The cap of an uncharged electroscope touches one end Q of the metal rod. A negatively charged ebonite rod is brought near the other end P of the metal rod.
(a) What charge does the end P have?
(b) What charge does the end Q have?
(c) What charge does the cap of the electroscope have?
(d) What charge does the gold leaf have?
(e) Will the leaf diverge or collapse? Give reason.
(f) If the electroscope is now earthed, what charge does the metal rod have?
