What is the function of the spiral spring in the construction of a galvanometer?

  • A
    To provide a restoring torque.
  • B
    To increase the magnetic field.
  • C
    To decrease the resistance of the coil.
  • D
    To support the weight of the coil.

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Similar Questions

$A$ galvanometer,having a resistance of $50 \Omega$,gives a full scale deflection for a current of $0.05 \text{ A}$. The length in metre of a resistance wire of area of cross-section $2.97 \times 10^{-2} \text{ cm}^2$ that can be used to convert the galvanometer into an ammeter which can read a maximum of $5 \text{ A}$ current is: (Specific resistance of the wire $= 5 \times 10^{-7} \Omega\text{-m}$)

$A$ shunt of resistance $1\ \Omega$ is connected across a galvanometer of $120\ \Omega$ resistance. $A$ current of $5.5\ A$ flows through the circuit,and the galvanometer shows full-scale deflection. What is the current that would cause full-scale deflection in the galvanometer in the absence of the shunt (in $A$)?

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The deflection in a moving coil galvanometer falls from $50$ divisions to $10$ divisions,when a shunt of $12 \Omega$ is connected with it. The resistance of the galvanometer coil is . . . . . . . (in $\Omega$)

Only $4 \%$ of the total current in the circuit passes through a galvanometer. If the resistance of the galvanometer is $G$,then the shunt resistance connected to the galvanometer is:

An ammeter whose resistance is $180\,\Omega$ gives full scale deflection when the current is $2\,mA$. The shunt required to convert it into an ammeter reading $20\,mA$ (in $\Omega$) is

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