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Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 25 July 2021, Shift 1, Physics Q11

Question 11 of 90 in this shift, Physics question 11 of 30, Section A.

In the given figure, there is a circuit of potentiometer of length AB = 10 m. The resistance per unit length is 0.1 Ω0.1\ \Omega per cm. Across AB, a battery of emf E and internal resistance 'r' is connected. The maximum value of emf measured by this potentiometer is :

The figure, in words

Potentiometer wire AB (10 m); jockey J divides it into AB-side 550 cm (A to J) and 450 cm (J to B). Cell E with internal resistance r and galvanometer G connected from A to J. Driver circuit across AB: 6 V battery in series with 20 ohm resistor and key K.
  1. (1)2.25 V
  2. (2)2.75 V
  3. (3)5 VOfficial answer
  4. (4)6 V

Official answer

Option 3

NTA final key.

Same topic in other shifts

All Potentiometer questions
  1. 4 Apr 2024, Shift 1 · Q50To measure the internal resistance of a battery, potentiometer is used. For R=10 ΩR = 10\ \Omega, the balance point is observed at l=500l = 500…MediumSingle correct
  2. 25 Jul 2022, Shift 2 · Q55In 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…EasyNumerical value
  3. 26 Jul 2022, Shift 2 · Q59A potentiometer wire of length 300 cm is connected in series with a resistance 780 Ω\Omega and a standard cell of emf 4V. A constant…MediumNumerical value
  4. 28 Jul 2022, Shift 1 · Q55As shown in the figure, a potentiometer wire of resistance 20 Ω\Omega and length 300 cm is connected with resistance box (R.B.) and a…HardNumerical valueHas a figure
  5. 24 Jun 2022, Shift 1 · Q59In a potentiometer arrangement, a cell gives a balancing point at 75 cm length of wire. This cell is now replaced by another cell of…EasyNumerical value
  6. 24 Jun 2022, Shift 2 · Q53A potentiometer wire of length 10 m and resistance 20 Ω\Omega is connected in series with a 25 V battery and an external resistance 30…MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.