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questions
List of practice Questions
The sum of the roots of the equation, \( x + 1 - 2\log_2(3 + 2^x) + 2\log_4(10 - 2^{-x}) = 0 \), is :
JEE Main - 2021
JEE Main
Mathematics
Quadratic Equations
If \( \alpha + \beta + \gamma = 2\pi \), then the system of equations
\( x + (\cos \gamma)y + (\cos \beta)z = 0 \)
\( (\cos \gamma)x + y + (\cos \alpha)z = 0 \)
\( (\cos \beta)x + (\cos \alpha)y + z = 0 \)
has :
JEE Main - 2021
JEE Main
Mathematics
Trigonometry
Let \( a_1, a_2, a_3, \dots \) be an A.P. If \( \frac{a_1 + a_2 + \dots + a_{10}}{a_1 + a_2 + \dots + a_p} = \frac{100}{p^2}, p \neq 10 \), then \( \frac{a_{11}}{a_{10}} \) is equal to :
JEE Main - 2021
JEE Main
Mathematics
Mathematics
An angle of intersection of the curves, \( \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 \) and \( x^2 + y^2 = ab, a>b \), is :
JEE Main - 2021
JEE Main
Mathematics
Mathematics
The empirical formula for a compound with a cubic close packed arrangement of anions and with cations occupying all the octahedral sites is $A_x B$. The value of $x$ is ________. (Integer answer)
JEE Main - 2021
JEE Main
Chemistry
The solid state
The value of magnetic quantum number of the outermost electron of $\text{Zn}^+$ ion is ________. (Integer answer)
JEE Main - 2021
JEE Main
Chemistry
Atomic Structure
1.22 g of an organic acid is separately dissolved in 100 g of benzene ($K_b = 2.6 \text{ K kg mol}^{-1}$) and 100 g of acetone ($K_b = 1.7 \text{ K kg mol}^{-1}$). The acid is known to dimerize in benzene but remain as a monomer in acetone. The boiling point of the solution in acetone increases by $0.17^\circ\text{C}$. The increase in boiling point of solution in benzene in $^\circ\text{C}$ is $x \times 10^{-2}$. The value of $x$ is ________. (Nearest integer) [Atomic mass : C = 12.0, H = 1.0, O = 16.0]
JEE Main - 2021
JEE Main
Chemistry
Colligative Properties
The pH of a solution obtained by mixing 50 mL of 1 M HCl and 30 mL of 1 M NaOH is $x \times 10^{-1}$. The value of $x$ is ________. (Nearest integer) [log 2.5 = 0.3979]
JEE Main - 2021
JEE Main
Chemistry
Ionic Equilibrium In Solution
$\text{CH}_4$ is adsorbed on 1 g charcoal at $0^\circ\text{C}$ following the Freundlich adsorption isotherm. 10.0 mL of $\text{CH}_4$ is adsorbed at 100 mm of Hg, whereas 15.0 mL is adsorbed at 200 mm of Hg. The volume of $\text{CH}_4$ adsorbed at 300 mm of Hg is $10^x$ mL. The value of $x$ is ________ $\times 10^{-2}$. (Nearest integer) [Use $\log_{10} 2 = 0.3010, \log_{10} 3 = 0.4771$]
JEE Main - 2021
JEE Main
Chemistry
Surface Chemistry
In the electrolytic refining of blister copper, the total number of main impurities, from the following, removed as anode mud is ________.
Pb, Sb, Se, Te, Ru, Ag, Au and Pt.
JEE Main - 2021
JEE Main
Chemistry
Metallurgy
Which among the following is not a polyester ?
JEE Main - 2021
JEE Main
Chemistry
Polymers
The deposition of X and Y on ground surfaces is referred as wet and dry depositions, respectively. X and Y are :
JEE Main - 2021
JEE Main
Chemistry
Environmental Chemistry
Which one of the following correctly represents the order of stability of oxides, \( X_2O \); (X = halogen) ?
JEE Main - 2021
JEE Main
Chemistry
properties of d block elements
Which one of the following statements is incorrect?
JEE Main - 2021
JEE Main
Chemistry
Hydrogen
The number of S=O bonds present in sulphurous acid, peroxodisulphuric acid and pyrosulphuric acid, respectively are :
JEE Main - 2021
JEE Main
Chemistry
properties of d block elements
A bandwidth of 6 MHz is available for A.M. transmission. If the maximum audio signal frequency used for modulating the carrier wave is not to exceed 6 kHz. The number of stations that can be broadcasted within this band simultaneously without interfering with each other will be ________.
JEE Main - 2021
JEE Main
Physics
communication systems
A particle is moving with constant acceleration 'a'. Following graph shows \(v^2\) versus x (displacement) plot. The acceleration of the particle is ________ m/s\(^2\).
\begin{center} \includegraphics[width=0.35\textwidth]{graph_v2_x} \end{center}
JEE Main - 2021
JEE Main
Physics
Kinematics
A long solenoid with 1000 turns/m has a core material with relative permeability 500 and volume \(10^3\) cm\(^3\). If the core material is replaced by another material having relative permeability of 750 with same volume maintaining same current of 0.75 A in the solenoid, the fractional change in the magnetic moment of the core would be approximately \(\left( \frac{x}{499} \right)\). Find the value of x.
JEE Main - 2021
JEE Main
Physics
Magnetism and matter
Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases are same. The ratio of the uncertainty in determining the position of an electron to that of a proton is proportional to :
JEE Main - 2021
JEE Main
Physics
Dual nature of matter
Four identical hollow cylindrical columns of mild steel support a big structure of mass $50 \times 10^3\,\text{kg}$. The inner and outer radii of each column are 50 cm and 100 cm respectively. Assuming uniform local load distribution, calculate the compression strain of each column. [use $Y = 2.0 \times 10^{11}\,\text{Pa}$, $g = 9.8\,\text{m/s}^2$]
JEE Main - 2021
JEE Main
Physics
mechanical properties of solids
A system consists of two identical spheres each of mass 1.5 kg and radius 50 cm at the ends of a light rod. The distance between the centres of the two spheres is 5 m. What will be the moment of inertia of the system about an axis perpendicular to the rod passing through its midpoint ?
JEE Main - 2021
JEE Main
Physics
System of Particles & Rotational Motion
A current of 1.5 A is flowing through a triangle, of side 9 cm each. The magnetic field at the centroid of the triangle is : (Assume that the current is flowing in the clockwise direction.)
JEE Main - 2021
JEE Main
Physics
Magnetic Effects Of Electric Current
Statement I : Two forces \((\vec{p} + \vec{q})\) and \((\vec{p} - \vec{q})\) where \(\vec{p} \perp \vec{q}\), when act at an angle \(\theta_1\) to each other, the magnitude of their resultant is \(\sqrt{3(p^2 + q^2)}\), when they act at an angle \(\theta_2\), the magnitude of their resultant becomes \(\sqrt{2(p^2 + q^2)}\). This is possible only when \(\theta_1<\theta_2\).
Statement II : In the situation given above, \(\theta_1 = 60^{\circ}\) and \(\theta_2 = 90^{\circ}\).
In the light of the above statements, choose the most appropriate answer from the options given below :
JEE Main - 2021
JEE Main
Physics
Vectors
A mixture of hydrogen and oxygen has volume 500 \(cm^3\), temperature 300 K, pressure 400 kPa and mass 0.76 g. The ratio of masses of oxygen to hydrogen will be :
JEE Main - 2021
JEE Main
Physics
The Kinetic Theory of Gases
A block moving horizontally on a smooth surface with a speed of 40 m/s splits into two parts with masses in the ratio of \(1 : 2\). If the smaller part moves at 60 m/s in the same direction, then the fractional change in kinetic energy is :
JEE Main - 2021
JEE Main
Physics
Work Power and Energy
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