MCQ
A small cylindrical soft iron piece is kept in a galvanometer so that
  • A
    A radial uniform magnetic field is produced
  • B
    A uniform magnetic field is produced
  • C
    There is a steady deflection of the coil
  • All of these

Answer

Correct option: D.
All of these
d
A soft iron core is used in a moving coil galvanometer. The soft iron core attracts the magnetic lines of force and hence the strength of the magnetic field increases if we use soft iron core. Thus the sensitivity of galvanometer increases. Also the use of soft iron core makes the magnetic field radial (i.e the plane of the coil will be always parallel to the direction of magnetic field).

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The magnetic flux linked with a coil at any instant $‘t’$ is given by $\phi$ $= 5\,t^3 -100t + 300$, the $e.m.f$. induced in the coil at $t = 2$ second is.......$V$
Two metallic rings $\mathrm{A}$ and $\mathrm{B}$, identical in shape and size but having different resistivities $\rho_A$ and $\rho_B$, are kept on top of two identical solenoids as shown in the figure. When current $I$ is switched on in both the solenoids in identical manner, the rings $\mathrm{A}$ and $\mathrm{B}$ jump to heights $h_A$ and $h_B$, respectively, with $h_A>h_B$. The possible relation$(s)$ between their resistivities and their masses $m_A$ and $m_B$ is(are)

$(A)$ $\rho_A>\rho_B$ and $m_A=m_B$

$(B)$ $\rho_A<\rho_B$ and $m_A=m_B$

$(C)$ $\rho_A>\rho_B$ and $m_A > m_B$

$(D)$ $\rho_A<\rho_B$ and $m_A < m_B$

The circuit shown in the figure consists of a battery of $emf$ $\varepsilon = 10 \,V$ ; a capacitor of capacitance $C = 1.0$ $ \mu F$  and three resistor of values $R_1 = 2$ $\Omega$ , $R_2 = 2$ $\Omega$ and $R_3 = 1$ $\Omega$ . Initially the capacitor is completely uncharged and the switch $S$ is open. The switch $S$ is closed at $t = 0.$
In the given figure net magnetic field at O will be
The relation between $I_p$ and $V_p$ for a triode is $\mathrm{I}_{\mathrm{p}}=\left(0.125 \mathrm{V}_{\mathrm{p}}-7.5\right) \mathrm{mA}$ , Keeping the grid potential constant at 1V, the value of $r_p$ will be
Which of the following statements concerning the depletion zone of an unbiased PN junction is (are) true
Force of attraction between two point charges $Q$ and $-Q$ separated by $d\,$ metre is ${F_e}$. When these charges are placed on two identical spheres of radius $R = 0.3\,d$ whose centres are $d\,$ metre apart, the force of attraction between them is
Which one of the following spherical lenses does not exhibit dispersion? The radii of curvature of the surfaces of the lenses are as given in the diagrams
Two plane mirrors are parallel to each other and an object $O$ is placed between them. Then the distance of the first three images from the mirror $M_2$ ​ will be (in $cm$)
A $TV$ transmission tower has a height of $140\, m$ and the height of the receiving antenna is $40\, m$. What is the maximum distance upto which signals can be broadcasted from this tower in $LOS$ (Line of Sight) mode?.........$km$ (Given : radius of earth $= 6.4 \times 10^6\, m$)