Assertion :Voltmeter always gives emf of a cell if it is connected across the terminals of a cell. Reason: Terminal potential of a cell is given by V=E−ir.
Assertion :Voltmeter always gives emf of a cell if it is connected across the terminals of a cell. Reason: Terminal potential of a cell is given by V=E−ir.
The correct option is D Assertion is incorrect but Reason is correct
By definition emf of a cell is the energy provided by a cell per coulomb of charge passing through it. Also batteries and cells have internal resistance(r), when electricity flows round the circuit the internal resistance of the cell itself resist the flow of current.
ε=I(R+r)
Where variables have their usual meanings
ε=IR+Ir
ε=V+Ir
V=ε−Ir
Where, V is the terminal potential difference across the terminals of the cell when current is flowing in the circuit, it is always less than emf of the cell.
If internal resistance of the cell is zero, no current will flow
through the cell and emf of cell is equal to the terminal potential difference across the terminals of the cell
By definition emf of a cell is the energy provided by a cell per coulomb of charge passing through it. Also batteries and cells have internal resistance(r), when electricity flows round the circuit the internal resistance of the cell itself resist the flow of current.
ε=I(R+r)
Where variables have their usual meanings
ε=IR+Ir
ε=V+Ir
V=ε−Ir
Where, V is the terminal potential difference across the terminals of the cell when current is flowing in the circuit, it is always less than emf of the cell.
If internal resistance of the cell is zero, no current will flow
through the cell and emf of cell is equal to the terminal potential difference across the terminals of the cell
