Advertisements
Advertisements
Question
The Figure below shows a potentiometer circuit in which the driver cell D has an emf of 6 V and internal resistance of 2 Ω. The potentiometer wire AB is 10 m long and has a resistance of 28 Ω. The series resistance RS is of 2 Ω.
- The current Ip flowing in the potentiometer wire AB when the jockey (J) does not touch the wire AB.
- emf of the cell X if the balancing length AC is 4.5 m.
Advertisements
Solution
- Resistance of 10 m wire AB = 28 Ω
Rs = 20 Ω
r = 2 Ω
∴ Total resistance (R) = (28 + 20 + 2) Ω = 50 Ω
`I_p = V/R`
= `6/50 A`
= 0.12 A - VAB = IP × RAB
= 0.12 × 28 V
= 3.36 V
emf of cell `X = Kl ...(("Here" K = 3.36/10 Vm^-1 = 0.336 Vm^-1),(and l = 4.5 m))`
X = 0.336 × 4.5 V
X = 1.512 V
APPEARS IN
RELATED QUESTIONS
State the advantages of potentiometer over voltmeter.
The net resistance of an ammeter should be small to ensure that _______________ .
A potentiometer wire has a length of 1.5 m and a resistance of 10 Ω. It is connected in series with the cell of emf 4 Volt and internal resistance 5 Ω. Calculate the potential drop per centimeter of the wire.
Why is a potentiometer preferred over a voltmeter for measuring emf?
It is observed in a potentiometer experiment that no current passes through the galvanometer when the terminals of the cell are connected across a certain length of the potentiometer wire. On shunting the cell by a 2 Ω resistance, the balancing length is reduced to half. The internal resistance of the cell is ______.
The sensitivity of the potentiometer can be increased by ______.
In a potentiometer circuit, a cell of EMF 1.5 V gives balance point at 36 cm length of wire. If another cell of EMF 2.5 V replaces the first cell, then at what length of the wire, the balance point occurs?
AB is a potentiometer wire (Figure). If the value of R is increased, in which direction will the balance point J shift?
Potential difference between the points A and B in the circuit shown is 16 V, then potential difference across 2Ω resistor is ______ V. volt. (VA > VB)
A cell of internal resistance r is connected across an external resistance nr. Then the ratio of the terminal voltage to the emf of the cell is ______.
