What is the sensitivity of a galvanometer?
The current sensitivity of a galvanometer is the deflection per unit current produced by the galvanometer. A high-sensitivity galvanometer can be used to measure very low values of currents. A low-sensitivity galvanometer can be used to measure high values of currents.
When the sensitivity of galvanometer is maximum?
So, a tangent galvanometer will be most sensitive when the deflection angle $ \theta = 45^\circ $ .
What are the factors affecting the sensitivity of a galvanometer?
It depends on number of turns, coil area, restoring force per unit twist, and magnetic field.
How do you increase the deflection of a galvanometer?
The deflection of the needle of galvanometer can be increased by:
- Increasing the number of the turns in the coil.
- Using a strong magnet.
- Increasing the speed with which magnet is moved in the coil.
What is meant by current sensitivity and voltage sensitivity of a galvanometer write two factors by which these sensitivity can be increased?
Current sensitivity or voltage sensitivity of a moving coil galvanometer can be increased by : (i) Increasing the number of turns in the galvanometer coil. (ii) Decreasing the torsion constant of the suspension fibre. Give the magnitude and direction of the net magnetic field due to the coils at their centre.
How can the sensitivity of moving coil galvanometer be increased?
So, sensitivity of the galvanometer can be increased either by increasing the number of turns (N), using strong magnets or increasing the area of the coil (A). So, the correct answer is that the sensitivity of a moving coil galvanometer can be increased by increasing the number of turns of the coil.
What is reduction factor of tangent galvanometer?
The reduction factor of tangent galvanometer is equal to current, and the unit of current is Ampere. So, the unit of reduction factor of tangent galvanometer is Ampere.
Does the voltage sensitivity of galvanometer increase by increasing no of turns in the coil of galvanometer answer with reason?
Current sensitivity can be increased by increasing the number of turns of the coil. Since voltage sensitivity decreases with increase in resistance of the coil, the effect of increase in number of turns is nullified in the case of voltage sensitivity. Hence, there is no increase in voltage sensitivity.
How could you increase the current sensitivity of a galvanometer by 50?
To increase the current sensitivity of a moving coil galvanometer by 50% its resistance is increased so that the new resistance becomes twice its initial resistance.
What are the factors on which voltage sensitivity depends?
Voltage sensitivity of galvanometer:It is defined as the deflection produced in the galvanometer when a unit voltage is applied across two terminals. Voltage sensitivity of a moving coil galvanometer is directly proportional to area of coil. It is directly proportional to magnetic field .
How can current sensitivity increase?
Current sensitivity can be increased by increasing the number of turns of the coil. Since voltage sensitivity decreases with increase in resistance of the coil, the effect of increase in number of turns is nullified in the case of voltage sensitivity.
What makes the sensitivity of a galvanometer higher?
The sensitivity of a galvanometer is higher if the instrument shows larger deflection for a small value of current. Sensitivity is of two types, namely current sensitivity and voltage sensitivity. The deflection θ per unit current I is known as current sensitivity θ/I
What happens to the resistance of a moving coil galvanometer?
An increase in current sensitivity of a moving coil galvanometer may not necessarily result in an increase in voltage sensitivity. As the number of turns (length of the coil) is increased to increase the current sensitivity of the device, the resistance of the coil changes.
How to calculate the current through a galvanometer?
When current I G passes through the galvanometer, the current through the shunt resistance is given by I S = I – I G. The voltages across the galvanometer and shunt resistance are equal due to the parallel nature of their connection. Therefore R G.I G = (I- I G).R s The value of S can be obtained using the above equation.
What is the torsion constant of a galvanometer?
K is the torsion-constant of the galvanometer, i.e., the spring constant of the spring that’s used in the galvanometer. R is the resistance of the coil. Now, increasing the number of turns N of the coil will result in the same increase in the resistance of the coil R as R∝ l and surface-area of the coil is kept stable.