NEET Pattern Practice Questions

Thirty Questions. Thirty Minutes. Go.

Section 15 taught you the fast way through this chapter — the verbatim statements, the moment-of-inertia table as recognition rather than derivation, the single-step numericals, the skater and incline templates, the two special formats, the elimination habits. This section finds out whether any of it survives contact with a clock.

There is no new physics below. There are 30 questions built the way this paper builds them, and one rule that matters more than the rest: you are being tested on pace, not on cleverness. If a question here takes you four lines of algebra, you have misread it.

How to attempt this set

Key Point: Blank sheet, pen, timer. Attempt all 30 questions in one unbroken sitting, and do not read a single explanation until your last answer is written. A drill you pause to check is a reading exercise, and reading exercises do not build speed.

[Important] The 30-minute limit is the entire exercise. Most students can get 27 of these right given an hour — and an hour is exactly what the real paper will not give you. Finishing in 30 minutes with 24 correct puts you in far better shape than taking 55 minutes to get 27. Keep the timer where you can see it, and the moment a question passes 60 seconds, mark your best surviving option and move on.

Here is the arithmetic that makes that instruction safe. A blind guess among four options is worth $\frac{4 - 3}{4} = +0.25$, essentially nothing. But once you have eliminated two options, a guess between the survivors is worth $\frac{4 - 1}{2} = +1.5$ marks on average. Eliminate first, then commit. Leave blank only what you could not narrow down at all.

What this set covers

That weighting is not arbitrary — it is how this paper actually samples the chapter. Moment of inertia is 4 of the 30 and torque with angular momentum another 4, because between them they are the most reliably repeated items here, and each is worth a whole mark in twenty seconds once the table is in your head. The last five drill the two formats this paper uses and the engineering papers do not: three assertion-reason items and two column matches. If you have never sat one of those under time pressure, they are the questions most likely to cost you marks.

[Important] Notice what is not in this set. No angular momentum about a randomly chosen point, no spin-plus-orbital decomposition, no rolling with slipping, no particle-hits-rod collisions, no toppling, and no moment of inertia by integration for cones or triangular plates. Those live in Sections 13 and 14. Every question below can be finished with one card from Section 15, one definition, or one right-angled triangle. If you find yourself wanting calculus, you are solving a question that is not on this page.

The difficulty mix is deliberately calibrated: roughly 35% easy, 45% medium and 20% hard.

Mark It Honestly, Then Read Your Own Answer Sheet

Score with the real scheme: $+4$ for every correct answer, $-1$ for every wrong one, $0$ for every blank. No half marks for "I nearly had that one". The number you end up with is the number that means something.

The bands

Sort your mistakes into three piles

Do this before you read a single explanation. It is the most useful ten minutes in this section.

1. Did not know it. A moment of inertia you could not recall, a unit you had never learnt precisely, the difference between what is conserved and what is not when a skater pulls her arms in. Cheapest to fix — it is a memory job, and it takes an evening.
2. Knew it, computed it wrong. You dropped the $\frac{1}{2}$ from $\frac{1}{2}I\omega^2$, you forgot to square the distance in $Md^2$, or you left an answer in revolutions when the question wanted radians. Slow down for four seconds on the final line.
3. Knew it, answered a different question. You gave the moment of inertia about the centre when it asked about the end; the rotational share of the kinetic energy when it asked for the translational; the angular speed after the change when it asked for the one before. The distractors here are built specifically to reward this mistake.

Key Point: Two students both score 88. The first has four pile-1 mistakes and a syllabus gap that revision closes in a day. The second has nine pile-3 mistakes and a reading habit that will follow them into the exam hall. Pile 3 is the expensive one — count it before you explain it away.

The ten recall facts this set keeps testing

• The centre of mass is $\vec{R} = \frac{\sum m_i\vec{r}_i}{M}$, it may lie where there is no material at all, and $M\vec{A} = \vec{F}_{ext}$ means internal forces can never move it.
• $\vec{P} = M\vec{V}_{cm}$, so zero external force means the centre of mass keeps its velocity forever, whatever the pieces do to one another.
• $\lvert \vec{a}\times\vec{b} \rvert = ab\sin\theta$ and the result is perpendicular to both. The cross product is anticommutative: reverse the order and you reverse the vector.
• $v = \omega r$, with $\omega$ in radians per second, and $\omega = 2\pi n$ where $n$ is in revolutions per second.
• $\tau = rF\sin\theta = F \times$ (perpendicular distance), measured in newton metres, and it is a vector even though its unit looks like the joule.
• $\vec{l} = \vec{r}\times\vec{p}$ and $L = I\omega$ for a fixed axis, unit kg m^2 s^-1, the same dimensions as Planck's constant.
• $\vec{\tau}_{ext} = \frac{d\vec{L}}{dt}$, so zero external torque means $L$ is constant and $I_1\omega_1 = I_2\omega_2$.
• Equilibrium needs BOTH $\sum\vec{F} = 0$ AND $\sum\vec{\tau} = 0$, and the principle of moments says load $\times$ load arm $=$ effort $\times$ effort arm.
• $I$ depends on the mass, on how it is distributed, and on the axis — never on the angular speed. $I = Mk^2$ defines the radius of gyration, and the two axis theorems are $I = I_{cm} + Md^2$ and $I_z = I_x + I_y$ (laminas only).
• Rolling means $v_{cm} = R\omega$, the total kinetic energy is $\frac{1}{2}Mv^2\left(1 + \frac{k^2}{R^2}\right)$, and down an incline the order is always solid sphere, disc, shell, ring.

One more pass, then move on

Every question below has a full step-by-step explanation and a note on why each wrong option is tempting. Read the explanation even for the questions you got right — on a paper this tight, the difference between a 20-second method and a 70-second method decides whether you finish Physics at all.

[Important] When you are done, do not immediately re-attempt the set. You would be scoring your memory of the answer key, not your physics. Leave it a week, then sit it again cold with the same 30-minute timer. The second score is the honest one.