JEE Main 2024 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 8 April 2024, Shift 2, Physics Q33

Question 33 of 90 in this shift, Physics question 3 of 30, Section A.

A given object takes n times the time to slide down

45^\circ

rough inclined plane as it takes the time to slide down an identical perfectly smooth

45^\circ

inclined plane. The coefficient of kinetic friction between the object and the surface of inclined plane is :

(1) $1-n^2$
(2) $1-\frac{1}{n^2}$ Official answer
(3) $\sqrt{1-n^2}$
(4) $\sqrt{1-\frac{1}{n^2}}$

Official answer

Option 2

NTA final key.

Chapter: Laws of Motion
Topic: Friction
Idea tested: Motion Down a Rough Incline

Same idea in other shifts

Asked 4× in all

4 Apr 2026, Shift 1 · Q28The time taken by a block of mass $m$ to slide down from the highest point to the lowest point on a rough inclined plane is $50\ \%$ more…MediumSingle correct
6 Apr 2026, Shift 2 · Q46A block takes $t$ time to slide down a plane inclined at $45^\circ$ to the horizontal. If the surface is made smooth (frictionless), the…MediumNumerical value
26 Feb 2021, Shift 2 · Q19An inclined plane making an angle of $30^\circ$ with the horizontal is placed in a uniform horizontal electric field $200\ \frac{N}{C}$ as…HardDiagram basedHas a figure

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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.