Advertisements
Advertisements
Question
Figure shows two circuits each having a galvanometer and a battery of 3V.
When the galvanometers in each arrangement do not show any deflection, obtain the ratio R1/R2.

Advertisements
Solution

For balanced wheat stone bridge, there will be no deflection in the galvanometer.
`4/R_1 = 6/9 => R_1 =(4 xx 9)/6 = 6Ω`
For the equivalent circuit, when the wheat stone bridge is balanced, there will be no deflection in the galvanometer.
`therefore 12/8 = 6/R_2 => R_2 \ ( 6xx 8)/12 = 4 Ω`
`therefore R_1/R_2 = 6/4 = 3/2`
RELATED QUESTIONS
A rectangular coil of a moving coil galvanometer contains 100 turns, each having area
15 cm2. It is suspended in the radial magnetic field 0.03 T. The twist constant of suspension
fibre is 15 x 10-10 N-m/degree. Calculate the sensitivity of the moving coil galvanometer.
Why is it necessary to introduce a radial magnetic field inside the coil of a galvanometer?
Define current sensitivity of a galvanometer.
The coil of a moving coil galvanometer is wound over a metal frame in order to ______.
The current sensitivity of a galvanometer increase by 20%. If its resistance also increases by 25%, the voltage sensitivity will ______.
How is current sensitivity increased?
A moving coil galvanometer of resistance 55 Ω produces a full scale deflection for a current of 250 mA. How will you convert it into an ammeter with a range of 0 - 3A?
To convert a moving coil galvanometer into an ammeter we need to connect a ______.
A galvanometer of resistance 100 Ω gives a full-scale deflection for a potential difference of 200 mV.
- What must be the resistance connected to convert the galvanometer into an ammeter of the range 0-200 mA?
- Determine resistance of the ammeter.
