MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Colour Coding of Resistors

In a potentio...

Question

In a potentiometer, the balance length with standard cadmium cell is 509 cm. The emf of a cell which when connected in the place of the standard cell gave a balanced length of 750 cm is (emf of the standard cell is 1.018V):

A

1.5V

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

B

0.5V

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

1.08V

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

1.2V

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A 1.5V
Let the Emf of cell be E

$\Rightarrow E_{c} = I \times r \times l_{1} [I_{1} = 509 c m]$

r - resistance per unit length of wire

$E = I \times r \times l_{2} [I_{2} = 750 c m]$

$\Rightarrow \frac{E_{c}}{E} = \frac{l_{1}}{l_{2}} = \frac{509}{750}$

$\Rightarrow \frac{1.018}{E} = \frac{509}{750}$

$E = 1.018 \times \frac{750}{509} = 1.5 V$

Suggest Corrections

thumbs-up

0

Similar questions

Q. Figure shows a potentiometer with a cell of 2.0 V and internal resistance 0.40

Ω

maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.02 V gives a balance point at 67.3 cm length of the wire. The standard cell is then replaced by a cell of unknown emf E and the balance point, similarly turns out to be at 82.3 cm, length of the wire. Then the E is

Q. In an experiment to determine the emf

E_{2}

of an unknown cell, its emf is compared with a standard cell of known emf

E_{1} = 1.12 V

. The balance point is obtained at

56 cm

with the standard cell and

80 cm

with the unknown cell. Determine the emf of the unknown cell.

Q. A standard cell of emf

E_{0} = 1.11 V

is balanced against

72 cm

length of a potentiometer. The same potentiometer is used to measure the potential difference across the standard resistance

R = 120 Ω

. When the ammeter shows a current of

7.8 mA

, a balanced length of

60 cm

is obtained on the potentiometer. Estimate the percentage error in the measurement of ammeter:

Q. In a potentiometer experiment of a cell of emf 1.25 V gives balancing length of 30 cm. If the cell is replaced by another cell, balancing length is found to be 40 cm. What is the emf of second cell?

150 c m

of a potentiometer wire is required to balance the emf of a cell. When a

5 Ω

resistor is connected across the terminals of the cell, the length required for balance is

125 c m

. The internal resistance of the cell is

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Ohm's Law in Scalar Form

PHYSICS

Watch in App

explore_more_icon

Explore more

Colour Coding of Resistors

Standard XII Physics

Join BYJU'S Learning Program

CrossIcon