Blog Log in Get Started Free

Physics MCQs for NEET — Practice Questions with Answers

Practice free Physics NEET multiple-choice questions online with instant answers and detailed explanations. No login required.

All Physics Chemistry Botany Zoology

Chapter Language Difficulty Show only questions I answered incorrectly Register free to filter questions

● ● ● ● ●

A liquid is flowing in a horizontal uniform capillary tube under a constant pressure difference P. The value of pressure for which the rate of flow of the liquid is doubled when the radius and length both are doubled is

$\frac{3 P}{4}$

$\frac{P}{2}$

$\frac{P}{4}$

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

(d) From

$V = \frac{{Pπr}^{4}}{8 ηl} \Rightarrow P = \frac{V 8 ηl}{{πr}^{4}} \Rightarrow \frac{P_{2}}{P_{1}} = \frac{V_{2}}{V_{1}} \times \frac{l_{2}}{l_{1}} \times {(\frac{r_{1}}{r_{2}})}^{4} = 2 \times 2 \times {(\frac{1}{2})}^{4} = \frac{1}{4} \Rightarrow P_{2} = \frac{P_{1}}{4} = \frac{P}{4}$

● ● ● ● ●

We have two (narrow) capillary tubes T₁ and T₂. Their lengths are l₁ and l₂ and radii of cross-section are r₁ and r₂ respectively. The rate of flow of water under a pressure difference P through tube T₁ is 8cm³/sec. If l₁ = 2l₂ and r₁ =r₂, what will be the rate of flow when the two tubes are connected in series and pressure difference across the combination is same as before (= P)

4 cm³/sec

(16/3) cm³/sec

(8/17) cm³/sec

None of these

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

(b) $V = \frac{{Pπr}^{4}}{8 ηl} \Rightarrow P = \frac{V 8 ηl}{{πr}^{4}}$

For composite tube

$V_{1} = \frac{{Pπr}^{4}}{8 η (l + \frac{l}{2})} = \frac{2}{3} \frac{{πPr}^{4}}{8 ηl} = \frac{2}{3} \times 8 = \frac{16}{3} \frac{{cm}^{3}}{\sec} [∵ l_{1} = l = 2 l_{2} or l_{2} = \frac{l}{2}]$

● ● ● ● ●

The Reynolds number of a flow is the ratio of

Gravity to viscous force

Gravity force to pressure force

Inertia forces to viscous force

Viscous forces to pressure forces

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

(c) $R_{e} = \frac{e v d}{η} o r R_{e} = \frac{e v^{2} d \times A}{A \times v \times η} \Rightarrow R_{e} = \frac{e v^{2} A}{η A v / d}$

Here, $η A v / d$ =viscous force and $e v^{2} A =$ Inertial force

Hence, $R_{e} = \frac{I n e r t i a l f o r c e}{v i s c o u s f o r c e}$

● ● ● ● ●

Water is flowing through a tube of non-uniform cross-section ratio of the radius at entry and exit end of the pipe is 3 : 2. Then the ratio of velocities at entry and exit of liquid is -

4 : 9

9 : 4

8 : 27

1 : 1

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

(a) If velocities of water at entry and exit points are v₁ and v₂, then according to equation of continuity,

$A_{1} V_{1} = A_{2} V_{2} \Rightarrow \frac{V_{1}}{V_{2}} = \frac{A_{2}}{A_{1}} = {(\frac{r_{2}}{r_{1}})}^{2} = {(\frac{2}{3})}^{2} = \frac{4}{9}$

● ● ● ● ●

An application of Bernoulli's equation for fluid flow is found in

Dynamic lift of an aeroplane

Viscosity meter

Capillary rise

Hydraulic press

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

Bernoulli's equation relates the pressure, velocity, and height of a flowing fluid. It is used to explain the dynamic lift of an aeroplane, where the faster air flow over the curved upper surface creates a lower pressure, resulting in an upward force on the wing.

● ● ● ● ●

The Working of an atomizer depends upon

Bernoulli's theorem

Boyle's law

Archimedes principle

Newton's law of motion

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

(a)

Atomizer works on the principle of liquid flow, It follows bernaulis principle because here, horizontal air passing causes the vertices liquid to come out.

● ● ● ● ●

The pans of a physical balance are in equilibrium. Air is blown under the right hand pan; then the right hand pan will

Move up

Move down

Move erratically

Remain at the same level

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

(b) According to Bernoulli's theorem.

● ● ● ● ●

According to Bernoulli's equation

$\frac{P}{ρg} + h + \frac{1}{2} \frac{v^{2}}{g} = constant$

The terms A, B and C are generally called respectively:

Gravitational head, pressure head and velocity head

Gravity, gravitational head and velocity head

Pressure head, gravitational head and velocity head

Gravity, pressure and velocity head

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

(c)

● ● ● ● ●

A sniper fires a rifle bullet into a gasoline tank making a hole 53.0 m below the surface of gasoline. The tank was sealed at 3.10 atm. The stored gasoline has a density of 660 ${kgm}^{- 3}$ . The velocity with which gasoline begins to shoot out of the hole is

27.8 ${ms}^{- 1}$

41.0 ${ms}^{- 1}$

9.6 ${ms}^{- 1}$

19.7 ${ms}^{- 1}$

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

The velocity of the gasoline shooting out of the hole can be calculated using Bernoulli's equation. The pressure difference between the inside of the tank and the atmospheric pressure provides the driving force for the flow, and the velocity depends on the height of the gasoline column.

● ● ● ● ●

A rectangular vessel when full of water takes 10 minutes to be emptied through an orifice in its bottom. How much time will it take to be emptied when half filled with water

9 minute

7 minute

5 minute

3 minute

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

(b) Time taken to be emptied for h height, $t = \sqrt{\frac{2 h}{g}}$

and for $\frac{h}{2}$ height , $t = \sqrt{\frac{2 h / 2}{g}} = \sqrt{\frac{h}{g}} ∴ \frac{t'}{t} = \frac{1}{\sqrt{2}} \Rightarrow t' = \frac{t}{\sqrt{2}} = \frac{10}{\sqrt{2}} = 7 minute$

Ready to ace NEET?

Free access · No credit card required

Browse All Questions Create Free Account

Frequently Asked Questions

Yes. You can attempt every Physics question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.

No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.

The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.