Advertisements
Advertisements
Question
Explain why does a metal wire when connected to a cell offer resistance to the flow of current.
Advertisements
Solution
A metal wire has free electrons which move in random directions. When the ends of the wire are connected to a cell, the electrons start moving from the negative terminal of the cell to its positive terminal through the metal wire. During their movement, they collide with the free electrons and fixed ions of the wire. This causes them to lose their speed and change their direction. As a result, the electrons slow down and slowly drift towards the positive terminal. Thus, the wire offers resistance to the flow of current (or electrons) through it.
APPEARS IN
RELATED QUESTIONS
What is a secondary cell?
Name the instrument used to control the current in an electric circuit.
'The resistance of a wire is 1 ohm'. Explain the meaning of this statement.
Calculate the total number of electrons flowing through a circuit in 20 mins and 40 s, if a current of 40 μA flows through the circuit.
[1 e– = 1.6 × 10-19 C]
State two characteristics of resistance in the parallel circuit.
A bulb is connected to a cell. How is the resistance of circuit affected if another identical bulb is connected (i) in series, (ii) in parallel, with the first bulb?
Explain the following:
Potential difference
