Advertisements
Advertisements
Question
SI unit of potential gradient is _______.
(a) V cm
(b) `V/"cm"`
(c) Vm
(d) `V/m`
Solution
`V/m`
APPEARS IN
RELATED QUESTIONS
Accuracy of potentiometer can be easily increased by ______.
Write two factors by which current sensitivity of a potentiometer can be increased.
(i) State the principle on which a potentiometer works. How can a given potentiometer be made more sensitive?
In the given circuit in the steady state, obtain the expressions for (a) the potential drop (b) the charge and (c) the energy stored in the capacitor, C.
Figure shows a long potentiometer wire AB having a constant potential gradient. The null points for the two primary cells of emfs ε1 and ε2 connected in the manner shown are obtained at a distance of l1 = 120 cm and l2 = 300 cm from the end A. Determine (i) ε1/ε2 and (ii) position of null point for the cell ε1 only.
Write two possible causes for one sided deflection in a potentiometer experiment.
When a resistor of 5Ω is connected across the cell, its terminal potential difference is balanced by 150 cm of potentiometer wire and when a resistance of 10 Ω is connected across the cell, the terminal potential difference is balanced by 175 cm same potentiometer wire. Find the balancing length when the cell is in open circuit and the internal resistance of the cell.
The net resistance of an ammeter should be small to ensure that _______________ .
Draw a labelled circuit diagram of a potentiometer to measure the internal resistance ‘r’ of a cell. Write the working formula (derivation is not required).
Draw a labelled circuit diagram of a potentiometer to compare emfs of two cells. Write the working formula (Derivation not required).
Define or describe a Potentiometer.
Why should not the jockey be slided along the potentiometer wire?
How is potential gradient measured? Explain.
Distinguish between a potentiometer and a voltmeter.
What will be the effect on the position of zero deflection if only the current flowing through the potentiometer wire is increased?
Describe with the help of a neat circuit diagram how you will determine the internal resistance of a cell by using a potentiometer. Derive the necessary formula.
Describe how a potentiometer is used to compare the emf's of two cells by the combination method.
Why is a potentiometer preferred over a voltmeter for measuring emf?
The resistance of a potentiometer wire is 8 Ω and its length is 8 m. A resistance box and a 2 V battery are connected in series with iL What should be the resistance in the box if it is desired to have a potential drop of 1 µV/mm?
The emf of a cell is balanced by a length of 120 cm of a potentiometer wire. When the cell is shunted by a resistance of 10 Ω, the balancing length is reduced by 20 cm. Find the internal resistance of the cell.
The SI unit of the potential gradient is ______
When the null point is obtained in the potentiometer, the current is drawn from the ______
A voltmeter has a resistance of 100 Ω. What will be its reading when it is connected across a cell of emf 6 V and internal resistance 20 Ω?
Which of the following instruments is not a direct reading instrument?
A potentiometer wire is 4m long and potential difference of 3V is maintained between the ends. The emf of the cell, which balances against a length of 100 cm of the potentiometer wire is ____________.
Sensitivity of a given potentiometer can be decreased by ______.
The length of a wire of a potentiometer is 100 cm, and the e.m.f of its standard cell is E volt. It is employed to measure the e.m.f of a battery whose internal resistance is 0.5 `Omega` If the balance point is obtained at `l`= 30 cm from the positive end, the e.m.f of the battery is ____________.
where 'i' is the current in the potentiometer
In the given figure, battery E is balanced on 55 cm length of potentiometer wire but when a resistance of 10 `Omega` is connected in parallel with the battery, then it balances on 50 cm length of the potentiometer wire. The internal resistance r of the battery is ____________.
A wire has a length of 2m and a resistance of 10Ω. It is connected in series with a resistance of 990Ω and a cell of e.m.f. 2V. The potential gradient along the wire will be ______
In the experiment to determine the internal resistance of a cell (E1) using a potentiometer, the resistance drawn from the resistance box is 'R'. The potential difference across the balancing length of the wire is equal to the terminal potential difference (V) of the cell. The value of internal resistance (r) of the cell is ______
If the length of potentiometer wire is increased, then the length of the previously obtained balance point will ______.
Two students X and Y perform potentiometer experiment separately and null point was obtained as shown in diagram. During the experiment, ______.
- X increases the value of R (resistance)
- Y decreases the value of S (resistance)
The position of null point obtained by students X and Y respectively.
In a potentiometer experiment when three cells A, B, C are connected in series the balancing length is found to be 740 cm. If A and B are connected in series, the balancing length is 440 cm and when B and C are connected in series, it is 540 cm. The e.m.f. of A, B, and C cells EA, EB, EC are respectively (in volt) ______
Potentiometer measures the potential difference more accurately than a voltmeter, because ______.
In a potentiometer experiment, for measuring internal resistance of a cell, the balance point has been obtained on the fourth wire. The balance point can be shifted to fifth wire by ______.
The sensitivity of the potentiometer can be increased by ______.
A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are obtained at 50 cm and 10 cm from the positive end of the wire in the two cases. The ratio of emf's is ______.
A wire of resistance R is cut into two equal part. There parts are then connected in parallel. The equivalent resistance of the combination will be
What is the current I in the circuit as show in fig.
Specific resistance of a conductor increase with.
1°C rise in temperature is observed in a conductor by passing a certain current. If the current is double then the rise in temperature is approximately.
The instrument among the following which measures the e.m.f of a cell most accurately is ______
In an experiment with a potentiometer, VB = 10V. R is adjusted to be 50Ω (Figure). A student wanting to measure voltage E1 of a battery (approx. 8V) finds no null point possible. He then diminishes R to 10Ω and is able to locate the null point on the last (4th) segment of the potentiometer. Find the resistance of the potentiometer wire and potential drop per unit length across the wire in the second case.
For the circuit shown, with R1 = 1.0 Ω, R2 = 2.0 Ω, E1 = 2 V, and E2 = E3 = 4 V, the potential difference between the points 'a' and 'b' is approximately (in V) ______.
In a potentiometer arrangement, a cell of emf 1.20 V gives a balance point at 36 cm length of wire. This cell is now replaced by another cell of emf 1.80 V. The difference in balancing length of potentiometer wire in above conditions will be ______ cm.
As a cell age, its internal resistance increases. A voltmeter of resistance 270 Ω connected across an old dry cell reads 1.44 V. However, a potentiometer at the balance point gives a voltage measurement of the cell as 1.5 V. Internal resistance of the cell is ______ Ω.
If you are provided a set of resistances 2Ω, 4Ω, 6Ω and 8Ω. Connect these resistances so as to obtain an equivalent resistance of `46/3`Ω.
The emf of the cell of internal resistance 1.275 Ω balances against a length of 217 cm of a potentiometer wire. Find the balancing length when the cell is shunted by a resistance of 15 Ω.
Draw a neat labelled diagram of Internal resistance of a cell using a potentiometer.
State dimension of potential gradient.
In a potentiometer, a cell is balanced against 110 cm when the circuit is open. A cell is balanced at 100 cm when short-circuited through a resistance of 10 Ω. Find the internal resistance of the cell.
