Advertisements
Advertisements
प्रश्न
Why does a galvanometer show a momentary deflection at the time of charging or discharging a capacitor? Write the necessary expression to explain this observation.
Advertisements
उत्तर
As the capacitor is connected to the battery, the electrons start moving towards the plate connected to the negative terminal of the battery and electrons leave from the plate connected to the positive terminal of the battery. This happens until the potential of the capacitor becomes equal to that of the battery. As this happens very quickly, the charging current produces a deflection. The reverse process is repeated for discharging that is the charge is lost. As the galvanometer can be considered as a resistance, the circuit behaves like a R-C circuit having time constant equal to RC. Hence the expression governing this phenomenon is
`q=q_0(1-e^(-t/(RC)))`
APPEARS IN
संबंधित प्रश्न
Show that the current flowing through a moving coil galvanometer is directly proportional to the angle of deflection of coil.
A circular coil of 250 turns and diameter 18 cm carries a current of 12A. What is the magnitude of magnetic moment associated with the coil?
Draw a labelled diagram of a moving coil galvanometer. Describe briefly its principle and working.
Increasing the current sensitivity of a galvanometer may not necessarily increase its voltage sensitivity. Explain, giving reason.
The fraction of the total current passing through the galvanometer is ............ .
a) `S/(S+G)`
b) `G/(S+G)`
c) `(S+G)/G`
d) `(S+G)/S`
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.
Define the term ‘current sensitivity’ of a moving coil galvanometer.
A galvanometer coil bas 500 turns and each tum has an average area of 3 × 10-4 m2. If a torque of 1.5 Nm is required to keep this coil parallel to a magnetic field when a current of 0.5 A is flowing through it, the strength of the field (in T) is ______.
A resistance of 3Ω is connected in parallel to a galvanometer of resistance 297Ω. Find the fraction of current passing through the galvanometer.
The figure below shows a circuit containing an ammeter A, a galvanometer G and a plug key K. When the key is closed:
