An ammeter $A$ of finite resistance, and a resistor $R$ are joined in series to an ideal cell $C$. $A$ potentiometer $P$ is joined in parallel to $R$. The ammeter reading is $I_0$ and the potentiometer reading is $V_0$. $P$ is now replaced by a voltmeter of finite resistance. The ammeter reading now is $I$ and the voltmeter reading is $V$.
Medium
Download our app for free and get startedPlay store
The potentiometer is almost an ideal voltmeter, hence the resistance of potentiometer is infinity.

current through potentiometer is very small, it does not draw any current from circuitwhen the potentiometer is replaced by voltmeter of finite resistance, the current through voltmeter is more than that of potentiometer. It means voltmeter draws some current from circuit.

hence $I > I 0$

Also $\mathrm{V}=I \mathrm{R}$ thus, $\mathrm{V} < \mathrm{Vo}$

art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    When a current flows through a conductor its temperature
    View Solution
  • 2
    In the circuit shown, the reading of ammeter when switch $S$ is open and when switch $S$ is closed respectively are
    View Solution
  • 3
    A copper wire of diameter $1.02\, mm$ carries a current of $1.7\, amp$. Find the drift  velocity $(v_d)$ of electrons in the wire. Given $n$, number density of electrons in copper $= 8.5 \times 10^{27} /m^3$....................... $mm/sec$
    View Solution
  • 4
    Which of the following quantities do not change when a resistor connected to a battery is heated due to the current?
    View Solution
  • 5
    Figure shows a cross-section of a large-section of an infinite metal sheet carrying an electric current along its surface. The current per unit length is $J$ . A current carrying square loop is placed nearby the metal sheet such that the plane of square is perpendicular to the plane of sheet then 
    View Solution
  • 6
    Potential gradient is defined as
    View Solution
  • 7
    $n$ equal resistors are first connected in series and then connected in parallel. What is the ratio of the maximum to the minimum resistance
    View Solution
  • 8
    The figure shows a tetrahedron, each side of which has a resistance $r$ Choose the correct diagram $(s),$ which show two-dimensional equivalent of the tetrahedron.
    View Solution
  • 9
    The resistance of a $5\, cm$ long wire is $10\, \Omega$. It is uniformly stretched so that its length becomes $20\, cm$. The resistance of the wire is ............. $\Omega$
    View Solution
  • 10
    Ratio of thermal energy released in two resistor $R$ and $3 R$ connected in parallel in an electric circuit is :
    View Solution