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प्रश्न
In Wheatstone’s meter-bridge experiment, the null point is obtained in the middle one-third portion of the wire. Why is it recommended?
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उत्तर
- Due to the non-uniformity of the bridge wire and the development of contact resistance at the wire's ends, the value of unknown resistance X may not be accurate.
- To reduce these errors, the value of R is modified so that the null point is found in the middle one-third of the wire (between 34 and 66 cm), resulting in the smallest and virtually identical percentage errors in the measurement of lx and lR.
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संबंधित प्रश्न
Four resistances 4Ω,8Ω,XΩ, and 6Ω are connected in a series so as to form Wheatstone’s
network. If the network is balanced, find the value of ‘X’.
Explain with a neat circuit diagram how will you determine unknown resistance ‘X' by using meter bridge
With the help of a labelled diagram, show that the balancing condition of a Wheatstone bridge is
`R_1/R_2 = R_3/R_4` where the terms have their usual meaning.
What should be the value of R in the figure for which the current in it is zero?
Obtain the balancing condition for the Wheatstone bridge arrangements as shown in Figure 4 below:
Four resistances 4 Ω, 8Ω, XΩ and 12Ω are connected in a series to form Wheatstone’s network. If the network is balanced, the value of X is ______.
Four resistances 6Ω, 6Ω, 6Ω and 18Ω form a Wheatstone bridge. Find the resistance which connected across the 18Ω resistance will balance the network.
Explain with a neat circuit diagram. How you will determine the unknown resistances using a meter bridge.
In a meter bridge, the balance point is found to be at 39.5 cm from the end A when the resistor R is 12.5 Ω (right gap).
a) Determine the resistance of X (left gap).
b) Determine the balance point of the bridge if X and R are interchanged?
c) What happens if the galvanometer and cell are interchanged at the balance point of the bridge?
With resistances P and Q placed in the left and right gaps of a metre bridge, the balance point divides the wire in the ratio of 1/3. When P and Q are increased by 40 n each. the balance point divides the wire in the ratio of 3/5. The values of P and Q will be respectively, ______
Two wires A and B of equal lengths are connected in left and right gap of a meter bridge, null point is obtained at 40 cm from left end. Diameters of the wire A and B are in that ratio 3 : 1. The ratio of specific resistance of A to the of B is ____________.
In a Wheatstone bridge, when the potentials at points B and D are the same, then the current through the galvanometer ______
With a resistance of 'X' in the left gap and a resistance of 9 Ω in the right gap of a meter bridge, the balance point is obtained at 40 cm from the left end.
In what way and to which resistance 3 Ω resistance be connected to obtain the balance at 50 cm from the left end?
The metre bridge works on the principle of ______.
In the metre bridge experiment shown in the figure, the balance length AC corresponding to null deflection of the galvanometer is x. What would be the balance length if the radius of the wire AB is doubled?
In Wheatstone's bridge P = 7 ohm, Q = 12 ohm, R = 3 ohm and S = 8 ohm. How much resistance must be put in parallel to the resistance S to balance the bridge?
In the network shown cell E has internal resistance r and the galvanometer shows zero deflection. If the cell is replaced by a new cell of emf 2E and internal resistance 3r keeping everything else identical, then ______.
In following figure, a current of 1.4 A flows towards the bridge circuit. The current in 2 n resistor is ______.
The potential difference between the points A and B in the electric circuit shown is ______.
Which among the following resistances can be determined by a metre bridge?
Two resistances prepared from the wire of the same material having diameters in the ratio 2 : 1 and lengths in the ratio 2 : 1 are connected in the left gap and right gap of Wheatstone's meter bridge respectively. The distance of the null point from the left end of the wire is ______
In a balanced metre bridge, 5 Ω is connected in the left gap and R Ω in the right gap. When R Ω is shunted with equal resistance, the new balance point is at 1.6 I1 where 'I1' is the earlier balancing length. The value of 'I1' is ______
In a meter bridge experiment, to minimize an error due to contact resistance, ______
In a metre bridge experiment, the ratio of the left-gap resistance to right gap resistance is 2: 3. The balance point from the left is ______.
ln, a Wheatstone network, P = Q = R = 8 `Omega` and S is 10 `Omega`. The required resistance to be connected to S so that network is balanced is ______.
The current through 1 `Omega` resistance in the following circuit is ______.
When an unknown resistance 'X' is connected in the left gap of a meter bridge and a known resistance 'R' in the right gap, a null point is obtained at 40 cm from the left end. If a 2 Ω resistance is connected in series with 'X' the null point shifts towards the right by 10 cm, with some resistance in the right gap. The value of 'X' must be ______
In a Wheatstone's bridge, the resistance in the three arms are P, Q, R, and its fourth arm has a parallel combination of two resistances S1 and S2, The balancing condition of the bridge is ______
The Wheatstone bridge is in a more balanced state when the ratio of arms P and Q is ______
A resistance of 20 Ω is connected in the left gap of a meter bridge and an unknown resistance greater than 20 Ω is connected in the right gap. When these resistances are interchanged, the balance point shifts by 20 cm. The unknown resistance is ______.
- Assertion (A): The given figure does not show a balanced Wheatstone bridge.
- Reason (R): For a balanced bridge small current should flow through the galvanometer.
In the given circuit, if I = 100 mA and I1 = I4 = 60 mA, the currents I3 and I5 are ______.
Explain the use of Wheatstone's metre bridge to determine an unknown resistance.
With an unknown resistance X in the left gap and a resistance of 30 Ω of the gap of a metre bridge, the null point is obtained at 40 cm from the left end of the wire. Find the unknown resistance. Also, find the shift in the null point when resistance in each gap is shunted by a resistance of 8 Ω.
Find the radius of the wire of length 25m needed to prepare a coil of resistance 25Ω. (Resistivity of material of wire is 3.142 x 10-7Ωm)
Four resistances 4Ω, 4Ω, 4Ω and 12Ω form a Wheatstone's network. Find the resistance which when connected across the 12Ω resistance will balance the network.
Write balancing condition of a Wheatstone bridge.
