NEET Part Test - 7 - NEET MCQ

# NEET Part Test - 7 - NEET MCQ

Test Description

## 180 Questions MCQ Test NEET Mock Test Series 2025 - NEET Part Test - 7

NEET Part Test - 7 for NEET 2024 is part of NEET Mock Test Series 2025 preparation. The NEET Part Test - 7 questions and answers have been prepared according to the NEET exam syllabus.The NEET Part Test - 7 MCQs are made for NEET 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for NEET Part Test - 7 below.
Solutions of NEET Part Test - 7 questions in English are available as part of our NEET Mock Test Series 2025 for NEET & NEET Part Test - 7 solutions in Hindi for NEET Mock Test Series 2025 course. Download more important topics, notes, lectures and mock test series for NEET Exam by signing up for free. Attempt NEET Part Test - 7 | 180 questions in 180 minutes | Mock test for NEET preparation | Free important questions MCQ to study NEET Mock Test Series 2025 for NEET Exam | Download free PDF with solutions
NEET Part Test - 7 - Question 1

### A wall is moving with constant velocity u towards a fixed source of sound of frequency 'f'. The velocity of sound is 'v'. The wavelength of the sound reflected by the wall is

Detailed Solution for NEET Part Test - 7 - Question 1

Frequency of sound reflected by wall f' =

∴ Wave length of sound reflected by wall =

NEET Part Test - 7 - Question 2

### In the figure shown, a small block of mass m moves in fixed semicircular smooth track of radius R in vertical plane. It is released from the top. The maximum centrifugal force on the block at the lowest point of track is.

 1 Crore+ students have signed up on EduRev. Have you?
NEET Part Test - 7 - Question 3

### A uniform thin rod of mass m and length R is placed normally on surface of earth as shown. The mass of earth is M and its radius is R. Then the magnitude of gravitational force exerted by earth on the rod is

Detailed Solution for NEET Part Test - 7 - Question 3

NEET Part Test - 7 - Question 4

At the middle of the mercury barometer tube there is a little column of air with the length and there is vacuum at the top as shown. Under the normal atmospheric pressure and the temperature of 300 kelvin,  = 10 cm. Neglect expansion of the tube. The length of the air column if the temperature rises to 330 kelvin will be -

Detailed Solution for NEET Part Test - 7 - Question 4

Pressure in the air inside the column of merucry is equal to the weight of mercury ove the air divided by the internal cross sectional area of the tube. when the temprature increase, the weight of the upper part of the mercury column does not change. That is why the pressure in the air is also constant. For the isobaric process, the change in volume is proportional to the change in temperature. The same is true for the lengths of the air column.

NEET Part Test - 7 - Question 5

A transverse periodic wave on a string with a linear mass density of 0.200 kg/m is described by the following equation y = 0.05 sin(420t – 21.0 x) where x and y are in metres and t is in seconds. The tension in the string is equal to :

Detailed Solution for NEET Part Test - 7 - Question 5

(μ = mass per unit length)

NEET Part Test - 7 - Question 6

A uniform thin rod of mass ‘m’ and length L is held horizontally by two vertical strings attached to the two ends. One of the string is cut. Find the angular acceleration soon after it is cut :

Detailed Solution for NEET Part Test - 7 - Question 6

Immediately after string connected to end B is cut, the rod has tendency to rotate about point A.
Torque on rod AB about axis passing through A and normal to plane of paper is -

Alternative
Applying Newton's law on center of mass
mg-T = ma       ..(I)
Writing τ = Iα about center of mass

..(II)

..(III)

From (i) , (ii) and (iii)

NEET Part Test - 7 - Question 7

Calculate moment of inertia of the system about axis AB shown in figure. Each segment of the system is made of a uniform wire of mass per unit length , where r is radius of each segment. The axis of full ring is along Y–axis. The axis of the semicircular rings are along x and z–axis. The centres of all rings coincide at the origin.

Detailed Solution for NEET Part Test - 7 - Question 7

NEET Part Test - 7 - Question 8

An aircraft moving with a speed of 972 km/h is at a height of 6000 m, just overhead of an anti-aircraft gun. If the muzzle velocity of the gun is 540 ms, the firing angle θ for the bullet to hit the aircraft should be

Detailed Solution for NEET Part Test - 7 - Question 8

Displacement of airctaft in time t = horizontal displacement of projectile

NEET Part Test - 7 - Question 9

A train is running at a speed of 108 km/hr. An inspection cart is also moving with a speed 10m/s in the same direction as train. The train hits the cart . The velocity of the cart after the collision is (in m/s) nearly.
(Assuming mass of train is much larger compared to mass of cart)

Detailed Solution for NEET Part Test - 7 - Question 9

From momentum conservation

M * 30 + m * 10 = Mv1 + mv2        ..(i)

e * velocity of approch = velocity of separation

on solving,

NEET Part Test - 7 - Question 10

An ice block at 0°C is dropped from height ‘h’ above the ground. What should be the value of ‘h’ so that it just melts completely by the time it reaches the bottom assuming the loss of whole gravitational potential energy is used as heat by the ice ? [Given : Lf = 80 cal/gm]

Detailed Solution for NEET Part Test - 7 - Question 10

Applying energy conservation :

mgh = mLf

NEET Part Test - 7 - Question 11

Find maximum amplitude for safe SHM(block does not topple during SHM) of a uniform cubical block of side 'a' on a smooth horizontal floor as shown in figure (sptring is massless) :

Detailed Solution for NEET Part Test - 7 - Question 11

NEET Part Test - 7 - Question 12

In the figure shown, the pulleys and strings are massless. The acceleration of the block of mass 4m just after the system is released from rest is

Detailed Solution for NEET Part Test - 7 - Question 12

The FBD of blocks is as shown

From Newton's second law

4mg - 2T cos θ = 4mA    ....(1)

and T - mg = ma     .....(2)

and from constraint we get a = A cos θ   ... (3)

solving equation (1) , (2) and (3)

we get acceleration of block of mass 4 m, a = 5g/11 downwards.

NEET Part Test - 7 - Question 13

In the figure shown, a light container is kept on a horizontal rough surface of coefficient of friction . A very small hole of area S is made at depth 'h'. Water of volume 'V' is filled in the container. The friction is not sufficient to keep the container at rest. The acceleration of the container initially is

Detailed Solution for NEET Part Test - 7 - Question 13

Let the density of water be ρ, then the force by escaping liquid on container =

∴ acceleration of container a =

NEET Part Test - 7 - Question 14

A solid sphere of iron at 2°C is lying at the bottom of a bucket full of water at 2°C. If the temperature of the water is increased to 3°C, the buoyant force on the sphere due to water will.

Detailed Solution for NEET Part Test - 7 - Question 14

As the temperature of water is increased from 2°C to 3°C the density of water increases (remember anamolous behaviour of water), also the volume of sphere increases. Therefore bouyant force on sphere due to water shall increase.

NEET Part Test - 7 - Question 15

Two sources S1 and S2 of same frequency f emits sound. The sources are moving as shown with speed u each. A stationary observer hears that sound. The beat frequency is (v = velocity of sound)

Detailed Solution for NEET Part Test - 7 - Question 15

Apparent frequency of Sand S2 heard by observer is

∴

NEET Part Test - 7 - Question 16

A body performs SHM along the straight line segment ABCDE with C as the mid point of segment AE (A and E are the extreme position for the SHM). Its kinetic energies at B and D are each one fourth of its maximum value. If length of segment AE is 2R, then the distance between B and D is

Detailed Solution for NEET Part Test - 7 - Question 16

When the particle crosses D, its speed is half the maximum speed.

NEET Part Test - 7 - Question 17

A wall is made of two layers A and B of the same thickness but different materials as shown. The thermal conductivity of A is thrice that of B. In steady state, the temperature difference across the wall is 360C. The temperature difference across the layer A is :

Detailed Solution for NEET Part Test - 7 - Question 17

The two are in series.

KA = 3KB

i.e thermal resistance of A(say RA) is one third that of B(say RB)

i.e RB = 3RA

∴ Temperature difference across 'A' =

NEET Part Test - 7 - Question 18

Man A is sitting in a car moving with a speed of 54 km/hr observes a man B in front of the car crossing perpendicularly a road of width 15 m in three seconds. Then the velocity of man B (in m/s) will be:

Detailed Solution for NEET Part Test - 7 - Question 18

Velocity of A and Velocity of B relative to A are as shown.

and direction of is away from

NEET Part Test - 7 - Question 19

In the figure shown, the minimum force F to be applied perpendicular to the incline so that the block does not slide is : (The block is always in contact with the incline)

Detailed Solution for NEET Part Test - 7 - Question 19

NEET Part Test - 7 - Question 20

A large open tank has two small holes in its vertical wall as shown in figure. One is a square hole of side 'L' at a depth '4y' from the top and the other is a circular hole of radius 'R' at a depth ‘y’ from the top. When the tank is completely filled with water, the quantities of water flowing out per second from both holes are the same. Then, 'R' is equal to :

Detailed Solution for NEET Part Test - 7 - Question 20

Let vand vbe the velocity of efflux from square and circular hole respectively. S1 and S2 be cross - section areas of square and circular holes.

The volume of water coming our of square and circular hole per second is

NEET Part Test - 7 - Question 21

When 97.52 is divided by 2.54, the correct result is

NEET Part Test - 7 - Question 22

Given that
where a = constant. Using dimensional analysis, the value of n is

NEET Part Test - 7 - Question 23

The value of n so that vectors  and   may be coplaner, will be

NEET Part Test - 7 - Question 24

A train passes an electric post in 8 seconds and a bridge of length 1km in 108 seconds. The speed of the engine is

NEET Part Test - 7 - Question 25

The negineer of a train moving at a speed v1 sights a freight train a distance d ahead of him on the same track moving in the same direction with a slow speed v2. He puts on the brakes and gives his train a constant deceleration α. Then there will be no collision if

NEET Part Test - 7 - Question 26

Which one of the following is consntant projectile motion ?

NEET Part Test - 7 - Question 27

Sixty four spherical rain drops of equal size are falling vertically through air with a terminal velocity 1.5 ms–1. If these drops coalesce to form a big spherical drop, then terminal velocity of big drop is

NEET Part Test - 7 - Question 28

The average force necessary to stop a bullet of 20 kg at a speed of 250 m/s as it penetrates wood to a distance of 12 cm is

NEET Part Test - 7 - Question 29

If a body is placed on another body which is accelerating by an external force then work done by frictional force on the upper body relative to ground is

NEET Part Test - 7 - Question 30

The work done by pseudo force is

NEET Part Test - 7 - Question 31

A pump can hoist 9000 kg of coal per hour from a mine of 120 m deep. Then the power in watts, assuming that its efficiency is 75% is

NEET Part Test - 7 - Question 32

Let ar and at represent radial and tangential acceleration. The motion of a particle may be circular if

NEET Part Test - 7 - Question 33

A rod is of length 3 m and its mass per unit length is directly proportional to the distance x from its one end. The cetnre of gravity of the rod from that end will be at

Detailed Solution for NEET Part Test - 7 - Question 33

Given that,

Length = 3 m

Let us consider an elementary length dx.

Its mass acting per unit length is directly proportional to distance x from one of its end.

Its mass  is

Where,

We need to calculate the center of gravity of the rod

Using formula of center of gravity

Put the value into the formula

Hence, The center of gravity from the end of the rod is 2 cm.