In the circuit shown, the reading of the Ammeter is doubled after the switch is closed. Each resistor has a resistance $1\,\Omega$ and the ideal cell has an $e.m.f.$ $10\,V$. Then, the Ammeter has a coil resistance equal to ............ $\Omega$
Diffcult
Download our app for free and get startedPlay store
(when switch is opened)

$10 \times 1 =\mathrm{i}_{1} \times(2+\mathrm{x})$

$\mathrm{i}_{1} =\frac{10}{2+\mathrm{x}}$

$\mathrm{i}_{2}=\frac{10}{\mathrm{x}}$

$\therefore \mathrm{i}_{2}=2 \mathrm{i}_{1}$

$\frac{10}{x}=2\left(\frac{10}{2+x}\right)$

$x=2\, \Omega$

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
    The variation of current $(I)$ and voltage $(V)$ is as shown in figure $A$. The variation of power $P$ with current $I$ is best shown by which of the following graph
    View Solution
  • 2
    In a sensitive meter bridge apparatus the bridge wire should possess
    View Solution
  • 3
    Four equal resistance dissipated $5 \,W$ of power together when connected in series to a battery of negligible internal resistance. The total power dissipated in these resistance when connected in parallel across the same battery would be ........... $W$
    View Solution
  • 4
    $\mathrm{A}$ circuit is comprised of eight identical batteries and a resistor $R = 0.8\,\Omega$ . Each battery has an $\mathrm{emf}$ of $1.0\, V$ and internal resistance of $0.2\,\Omega$ . The voltage difference across any of the battery is ............. $V$
    View Solution
  • 5
    The equivalent resistance between points $A$ and $B$ in the given network is ............ $\Omega$
    View Solution
  • 6
    Two resistance wires on joining in parallel the resultant resistance is $\frac{6}{5}\,ohms$. One of the wire breaks, the effective resistance is $2\,ohms$. The resistance of the broken wire is ............ $ohm$
    View Solution
  • 7
    In the circuit shown in figure, the power which is dissipated as heat in the $6\,\Omega$ resistor is $6\,W$. What is the value of resistance $R$ in the circuit?................... $\Omega$
    View Solution
  • 8
    If an observer is moving with respect to a stationary electron, then he observes
    View Solution
  • 9
    Resistances of $6\, ohm$ each are connected in the manner shown in adjoining figure. With the current $0.5\,ampere$ as shown in figure, the potential difference ${V_P} - {V_Q}$ is .............. $V$
    View Solution
  • 10
    The temperature coefficient of resistance for a wire is $0.00125\,^oC$. At  $300\,K$ its resistance is $1\, ohm$. The temperature at which the resistance becomes $2\, ohm$ is .......... $K$
    View Solution