JEE  >  JEE Main Physics Mock - 4

# JEE Main Physics Mock - 4

Test Description

## 25 Questions MCQ Test JEE Main & Advanced Mock Test Series | JEE Main Physics Mock - 4

JEE Main Physics Mock - 4 for JEE 2022 is part of JEE Main & Advanced Mock Test Series preparation. The JEE Main Physics Mock - 4 questions and answers have been prepared according to the JEE exam syllabus.The JEE Main Physics Mock - 4 MCQs are made for JEE 2022 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests for JEE Main Physics Mock - 4 below.
Solutions of JEE Main Physics Mock - 4 questions in English are available as part of our JEE Main & Advanced Mock Test Series for JEE & JEE Main Physics Mock - 4 solutions in Hindi for JEE Main & Advanced Mock Test Series course. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free. Attempt JEE Main Physics Mock - 4 | 25 questions in 60 minutes | Mock test for JEE preparation | Free important questions MCQ to study JEE Main & Advanced Mock Test Series for JEE Exam | Download free PDF with solutions
 1 Crore+ students have signed up on EduRev. Have you?
JEE Main Physics Mock - 4 - Question 1

### Suppose an electron is attracted towards the origin by a force k/r where 'k' is a constant and 'r' is the distance of the electron from the origin . By applying Bohr model to this system , the radius of the nth orbital of the electron is found to be 'r'n and the kinetic energy of the electron to be Tn . Then which of the following is true ?

JEE Main Physics Mock - 4 - Question 2

### The energy of a photon of wavelength (λ) is

JEE Main Physics Mock - 4 - Question 3

### For a given material, the Young's modulus is 2.4 times that of rigidity modulus. Its Poisson's ratio is

Detailed Solution for JEE Main Physics Mock - 4 - Question 3
JEE Main Physics Mock - 4 - Question 4
Two spherical conductors of radii 4 cm and 5 cm are charged to the same potential. If σ₁ and σ₂ be the respective values of the surface density of charge on both the conductors, then the ratio σ₁/σ₂ is
JEE Main Physics Mock - 4 - Question 5

If 3.8 x 10-6 is added to 4.2 x 10-5 giving due regard to significant figures, then the result will be

JEE Main Physics Mock - 4 - Question 6
A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer is
Detailed Solution for JEE Main Physics Mock - 4 - Question 6 Efficiency= (output power/input power)*100
=>(90*11/220*5)*100
90%
JEE Main Physics Mock - 4 - Question 7

A parallel plate capacitor is first charged and then a dielectric slab is introduced between the plates after disconnecting it from the battery. The quantity that remains unchanged is

JEE Main Physics Mock - 4 - Question 8
Spot the wrong statement : The acceleration due to gravity decreases if
JEE Main Physics Mock - 4 - Question 9
For Boyle's law to hold the gas should be
JEE Main Physics Mock - 4 - Question 10

When two deuterium nuclei fuse together, in addition to tritium, we get a

Detailed Solution for JEE Main Physics Mock - 4 - Question 10

JEE Main Physics Mock - 4 - Question 11

If two bodies are projected at 30o and 60o respectively, with the same velocity, then

JEE Main Physics Mock - 4 - Question 12
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): A uniform solid cylinder rolling with angular velocity ω along a plane surface strikes a vertical rigid wall. Angular velocity of cylinder when it begins to roll up a wall is less than the initial Angular velocity (ω).
Reason(R): After striking the vertical wall angular velocity increases.
JEE Main Physics Mock - 4 - Question 13
In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Current is passed through a metallic wire heating it red. When cold water is poured on half of its portion, the rest of half portion becomes more hot.
Reason(R): Resistance decreases due to decrease in temperature and then current through wire increases.
JEE Main Physics Mock - 4 - Question 14
A disc is placed on a surface of pond which has refractive index 5/3. A source of light is placed 4 m below the surface of liquid. The minimum radius of disc needed so that light is not coming out is
JEE Main Physics Mock - 4 - Question 15
Sound waves transfer
JEE Main Physics Mock - 4 - Question 16

The wavelength of ultrasonic waves in air is of the order of

JEE Main Physics Mock - 4 - Question 17

70 calories of heat are required to raise the temperature of 2 moles of an ideal gas at constant pressure from 30oC to 35oC. The amount of heat required to raise the temperature of the same sample of the gas through the same range at constant volume is nearly (Gas constant = 1.99 cal/K-mole)

Detailed Solution for JEE Main Physics Mock - 4 - Question 17
Cp= q/n*delta t
= 70/2*5=7
We know that for diatomic gas
Cp/Cv=7/5
So Cv=5
Cv=q/n*delta t
5=q/2*5
q=50 calories
JEE Main Physics Mock - 4 - Question 18
Both light and sound waves produce diffraction. It is more difficult to observe the diffraction with light waves because
JEE Main Physics Mock - 4 - Question 19

A boy of mass 42 Kg eats bananas of 980 calories. If this energy is used up to lift him from the ground, the height to which he can move up is

Detailed Solution for JEE Main Physics Mock - 4 - Question 19

Height = h.
Potential Energy (P.E) = 980 Calories = 4100.32 Jule
Now P.E = mgh
4100.32 = 42 x 9.8 x h
h = 4100.32/42x9.8 ≈ 10m

JEE Main Physics Mock - 4 - Question 20

In the given circuit the capacitor (C) may be charged through resistance R by battery V by closing switch S1. Also when S1 is opened and S2 is closed the capacitor is connected in series with inductor (L).

Q. At the start, the capacitor was uncharged. When switch S1 is closed and S2 is kept open, the time constant of this circuit is τ. Which of the following is correct?

*Answer can only contain numeric values
JEE Main Physics Mock - 4 - Question 21

A plastic circular disc of radius 10 cm is placed on a thin oil film of thickness 2 mm, spread over a flat horizontal surface. The torque (N-m) required to spin the disc about its central vertical axis with a constant angular velocity 8 rad/sec is  (coefficient of viscosity of oil is 1.0 kg/m-s) (take π = 3.14)

Detailed Solution for JEE Main Physics Mock - 4 - Question 21

*Answer can only contain numeric values
JEE Main Physics Mock - 4 - Question 22

Calculate the value of output voltage V0 (in V) if the Si diode and Ge diode conduct at 0.7 V and 0.3V respectively as shown in figure.

Detailed Solution for JEE Main Physics Mock - 4 - Question 22

*Answer can only contain numeric values
JEE Main Physics Mock - 4 - Question 23

In Young's double slit experiment, the wavelength of red light is 7800 Å and that of blue light is 5200 Å. The minimum value of n for which nth bright band due to red light coincides with (n + 1)th bright band due to blue light, is :

Detailed Solution for JEE Main Physics Mock - 4 - Question 23

n (7800) = (n + 1) 5200

*Answer can only contain numeric values
JEE Main Physics Mock - 4 - Question 24

A railway track (made of iron) is laid in winter when the average temperature is 18°C. The track consists of sections of 12.0 m  placed on after the other. How much gap (in cm) should be left between two such sections so that there is no compression during summer when the maximum temperature goes to 48°C ? Coefficient of linear expansion of iron = 11 × 10–6/°C.

Detailed Solution for JEE Main Physics Mock - 4 - Question 24

ΔL = L0 α ΔT
= 12 × 11 × 10–6 × 30
= 3960 × 10–6 m

*Answer can only contain numeric values
JEE Main Physics Mock - 4 - Question 25

A string of mass per unit length μ is clamped at both ends such that one end of the string is at x = 0 and the other end at x = L. When string vibrates in fundamental mode, amplitude of the midpoint of string is a and tension in string is F. Find the total oscillation energy (in J) stored in the string. (Use L = 1m, F = 10 N,  a = 1/πm)

Detailed Solution for JEE Main Physics Mock - 4 - Question 25

## JEE Main & Advanced Mock Test Series

2 videos|324 docs|160 tests
 Use Code STAYHOME200 and get INR 200 additional OFF Use Coupon Code
Information about JEE Main Physics Mock - 4 Page
In this test you can find the Exam questions for JEE Main Physics Mock - 4 solved & explained in the simplest way possible. Besides giving Questions and answers for JEE Main Physics Mock - 4, EduRev gives you an ample number of Online tests for practice

## JEE Main & Advanced Mock Test Series

2 videos|324 docs|160 tests