JEE Main Practice Test- 28 - JEE

Which of the following is true?

A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 m/sec. A plump bob is suspended from the roof of the car by a light rigid rod of length 1.00 m. The angle made by the rod with track is

The approximated wavelength of a photon of energy 2.48eV is

A point Q lies on the perpendicular bisector of an electrical dipole of dipole moment p. If the distance of Q from the dipole is r (much larger than the size of the dipole), then the electric field at Q is proportional to :

The electric field at the centroid of an equilateral triangle carrying an equal charge q at each of the vertices is

A lift of mass 1000 kg is moving with an acceleration of 1 m−s⁻² in upward direction. Tension developed in the string, which is connected to the lift, is

A machine gun fires a bullet of mass 40 g with a velocity 1200 m−s⁻1. The man holding it can exert a maximum force of 144 N on the gun. How many bullets can he fire per second at the most?

A long solenoid has n turns per metre and current I ampere is flowing through it. The magnetic field at the ends of solenoid is

The logic behind 'NOR' gate is that, it gives

Two pieces of a glass plate, placed one upon the other with a little water in between them, can not be separated easily, because of

The function of the moderator in a nuclear reactor is

The sum of two vectors A → and B → is at right angles to their difference. Then

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):In a nuclear reactor cadmium acts as a moderator.
Reason(R):The cadium rods are so inserted in the graphite block so that they can be slided in and out as per requirement.

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): Energy density in the solenoid is greater at centre than near its ends.
Reason(R): Energy density is defined as 

A solid cylinder of mass M and radius R rolls down an inclined plane without slipping. The speed of its centre of mass when it reaches the bottom is

There are two lead spheres at the same temperature, the ratio of radii being 1:2 The ratio of head capacities are

For the constructive interference the path difference between the two interfering waves must be equal to

The fundamental unit which has the same power in the dimensional formula of surface tension and viscosity is

If a star is moving towards earth, then the lines are shifted towards

A parallel monochromatic beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of slit is

When a tuning fork of frequency 341 is sounded with another tuning fork, six beats per second are heard. When the second tuning fork is loaded with wax and sounded with the first tuning fork, the number of beats is two per second. The natural frequency of the second tuning fork is

d/dx [tan^-1 cosx/(1 + sin x)] =

Singly ionized helium (He⁺) atom is hydrogen like in the sense that a solitary electron revolves around a positively charged nucleus. If the energy of this electron in its first orbit (n = 1) is -54.4 eV, what will be its energy in the first excited state?

The charge deposited on 4 μ F capacitor in the circuit is

The angular velocity of the second needle in watch (in rad/s) is

We are able to obtain fairly large currents in a conductor because

A charge +4q is located on the X-axis of a Cartesian coordinate system at x = -2a as shown. Another charge +(q/4) is located on the X-axis at x = a. Where on the Y-axis should a third charge -3q be placed so that the resultant electric field at the origin O has equal positive X and Y components?

A charged particle with velocity 2 x 10³ m/s passes undeflected through electric and magnetic field. Magnetic field is 1.5 telsa. The electric field intensity would be

The correct order of boiling points for primary (1º), secondary (2º) and tertiary (3º) alcohols is

Which of the following does not undergo Cannizzaro's reaction?

DNA has deoxyribose, base and a third compound, known as

For reaction at equilibrium, Le Chatelier's principle predicts the effects of

For an endothermic reaction, energy of activation is E_a and enthalpy of reaction is ΔH (both of these in kJ/mol). Minimum value of E_a will be

In the reaction CH₂COOH_aq + OH_(aq) → CH₃COO^- + H₂O_(l) ; ΔH = -55.2kJ mol^-1 What is the heat of dissociation (in kJ mol^-1) of acetic acid?

Element with Atomic number 38, belongs to

Which of the following complexes will have four isomers?

Compound A has a molecular formula C₇H₇NO on treatment with Br₂/KOH, A gives an amine B which respond to carbylamine test. B on diazotisation and coupling with phenol give an azo dye. A can be

The amount of Aluminium deposited when 0.1 Faraday current is passed through aluminium chloride will be (R = 27)

A solution of AgNO₃ during electrolysis between silver electrodes required a quantity of 241.25 coulombs of electricity the weight of silver deposited is

pH of a solution is defined by the expression

To a solution containing equimolar mixture of sodium acetate and acetic acid, some more amount of sodium acetate solution is added. The pH of mixture solution

Identify the indicator used to titrate Na₂CO₃ solution with HCl

A white salt is readily soluble in water and gives a colourless solutions with a pH of about 9.The salt would be

Which of the following compounds will show positive silver mirror test?

Among the following compounds the decreasing order of reactivity towards electrophilic substitution is:

Which is not a macromolecule?

For preparing an alkane ,a concentrated aqueous solution of sodium or potassium salt of a saturated carboxylic acid is subjected to

AB is an ionic solid. If the ratio of ionic radii of A⁺ and B ⁻ is 0 . 52. What is the coordination number of B ⁻

The solubility of gas in liquid increases with

Which of the following is not a crystalline solid ?

A 100 g solution contains 25 g of water, 25 g ethanol and 50 g acetic acid. The mole fraction of water is

Pent-1-ene with HCl gives

Which of the following statements is incorrect?

Entropy of universe:

An activated complex molecule differs from a normal molecule of the same atomicity in that it has__

The electrons, identified by quantum numbers n,l (i) n = 4, l = 1, (ii) n = 4, l = 0, (iii) n = 3, l = 2, (iv) n = 3, l = 1 can be placed in order of increasing energy, from the lowest to highest, as_

Which one of the following platinum complexes is used in cancer chemotherapy?

If 0.6387 of plantinichloride of a monoacid base on ignition gave 0.209g of platinum, then molecular weight of the base is

The area, in square unit, of the region bounded by the curve x² = 4 y , the line x = 2 and the x-axis is

When 5⁹⁹ is divided by 13 then the remainder is

What is the value of x satisfying the equation
?

The equation of the circle described on the common chord of the circles x² + y² -8x + y -15 = 0 and x² + y² - 4x + 4y - 42 = 0 as diameter is

If p and q are the roots of the equation x² + px + q = 0, then

i²⁴³ =

If z lies on |z| = 1 ,then 2/z lies on

The solution of the equation y - x(dy/dx)=a[(y²)+(dy/dx)] is

"If Deb and Sam go to the mall, then it is snowing."
Which statement below is logically equivalent?

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-
A committee of n persons is to be formed out of 30 persons.
Assertion(A) : The value of n for which the number of committees is maximum is n = 15
Reason(R) : In the expansion of the middle term has the greatest binomial coefficient.

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):The angle between the lines 2x = 3y = -z and 6x = - y = - 4z , is 90⁰ .
Reason(R): If and   and angle between them is θ , then 

If 

A and B are square matrices of order n x n, then (A - B)² is equal to

The equation of the normal to the curve x² = 4y at (1, 2) is

If ²ⁿC₃:ⁿC₂=44:3.For which value of r, ⁿC_r=15?

If a dice is thrown twice, the probability of occurrence of 4 at least once, is

A student obtain 75%, 80% and 85% in three subjects. If the marks of another subject are added, then his average cannot be less than

The angle between lines 3x+y-7=0 and x+2y+9=0 is

The equation of the sphere passing thro' the point (1,3-2) and the circle y²+z²=25 and x=0 is

If (axb)²+(a.b)²=144 and |a|=4, then |b|=

Given that θ is a acute and that sin θ =3/5. Let x,y be positive real numbers such that 3(x-y) =1, then one set of solutions for x and y expressed in terms of θ is given by

The length of subtangent to x² + xy + y² = 7 at 1, − 3 is

If a=i+2j-2k, b=2i-j+k, c=i+3j-k, then ax(bxc)=

A and B are non - zero square matrices of the same order. Which is correct?

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):
Reason(R): If f(x) is a periodic function of period a, then

If minimum value of f(x) = x² + 2bx + 2c² is greater than maximum value of g(x) = - x² - 2cx + b² then for x is real

Let f(x) =ax²+bx+c,a≠0 and triangle = b²-4ac.If α+β, α²+β² and α²+β² are in G.P., then :