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Saturday, 10 October

JEE Main 2025 · PhysicsMultiple choiceDiagram basedMediumCalculation

JEE Main 7 April 2025, Shift 1, Physics Q38

Question 38 of 75 in this shift, Physics question 13 of 25, Section A.

Two charges q1q_1 and q2q_2 are separated by a distance of 30 cm. A third charge q3q_3 initially at 'C' as shown in the figure, is moved along the circular path of radius 40 cm from C to D. If the difference in potential energy due to movement of q3q_3 from C to D is given by q3K4πϵ0\frac{q_3 K}{4\pi\epsilon_0}, the value of K is:

The figure, in words

q1 at A (bottom left) and q2 at B on the horizontal line, AB = 30 cm; D lies on the same line beyond B; q3 initially at C directly above A with AC = 40 cm; dashed circular arc of radius 40 cm from C to D.
  1. (1)8q18q_1
  2. (2)6q26q_2
  3. (3)6q16q_1
  4. (4)8q28q_2Official answer

Official answer

Option 4

NTA final key.

Chapter
Electrostatic Potential and Capacitance
Topic
Electric Potential
Idea tested
Work Done in Field

Same topic in other shifts

All Electric Potential questions
  1. 6 Apr 2026, Shift 2 · Q37The electric potential as a function of x,yx, y is given by V=5(x2−y2)V=5(x^2-y^2) V. The electric field at a point (2, 3) m is __________ V/m.EasySingle correct
  2. 6 Apr 2026, Shift 2 · Q40A sphere of capacitance 100 pF is charged to a potential of 100 V. Another identical uncharged metal sphere is brought in contact with the…MediumSingle correct
  3. 2 Apr 2025, Shift 2 · Q42Two large plane parallel conducting plates are kept 10 cm apart as shown in figure. The potential difference between them is V. The…MediumDiagram basedHas a figure
  4. 3 Apr 2025, Shift 1 · Q39The electrostatic potential on the surface of uniformly charged spherical shell of radius R = 10 cm is 120 V. The potential at the centre…EasySingle correct
  5. 8 Apr 2025, Shift 2 · Q35Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : Work done in moving a…EasyAssertion–reason
  6. 9 Apr 2024, Shift 1 · Q55At the centre of a half ring of radius R=10R=10 cm and linear charge density 4 nC m−14\ \mathrm{nC\,m^{-1}}, the potential is xπx\pi V. The value…EasyNumerical 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 42 of the 174 JEE Main shifts held from 2017 to 2026.