Ch4- Moving Charges and Magnetism :Moving Coil Galvanometer

In moving coil galvanometer, the pole faces of U-shaped magnet are made concave

• to make the field radial

• to increase the field

• to weaken the field

• both (a) and (b)

In a moving coil galvanometer, the deflection of the coil Φ is related to the electric current i by the relation

• I ∝ tanΦ

• I ∝ Φ

• I ∝ Φ²

• I ∝ tan²Φ

The sensitivity of a moving coil galvanometer can be increased by decreasing

• the number of turns in the coil

• the area of the coil

• the magnetic field

• the restoring torque per unit twist of the suspension

A moving coil galvanometer has N number of turns in a coil of effective area A, it carries a current I. The magnetic field B is radial. The torque acting on the coil is

• NA²B²I

• NABI²

• N²ABI

• NABI

Formula for figure of merit of galvanometer

•  $\frac{k}{\left(R-G\right)\theta}$  

•  $\frac{k}{\left(R+G\right)\theta}$  

What is meant by the figure of merit of a galvanometer?

• Maximum deflection on the galvanometer

• Current required to produce unit deflection on the galvanometer

• Voltage required to produce unit deflection on the galvanometer

What is the principle of Moving Coil Galvanometer.

• Current carrying coil in an electric field experiences a force

• Current carrying coil in magnetic field experiences no force

• Current carrying conductor in magnetic field experiences a force

• Current carrying conductor in an electric field produces no force

The ratio of voltage sensitivity (  $V_s$ ) and current sensitivity ( $I_s$  ) of a moving coil galvanometer is (G =conductance)

•  $\frac{1}{G}$  

•  $\frac{1}{G^2}$  

•  $G$  

•  $G^2$  

Which rule can be used to work out which way a coil of wire rotates in a motor?

• Fleming's left-hand rule

• Fleming's right-hand rule

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5

The direction of the force on a current-carrying wire placed in a magnetic field depends on

• the direction of the current

• the direction of the field

• the direction of current as well as field

• neither the direction of current nor the direction of field