JEE Main MCQ & Objective Questions
The JEE Main exam is a crucial step for students aspiring to enter prestigious engineering colleges in India. It tests not only knowledge but also the ability to apply concepts effectively. Practicing MCQs and objective questions is essential for scoring better, as it helps in familiarizing students with the exam pattern and enhances their problem-solving skills. Engaging with practice questions allows students to identify important questions and strengthen their exam preparation.
What You Will Practise Here
Fundamental concepts of Physics, Chemistry, and Mathematics
Key formulas and their applications in problem-solving
Important definitions and theories relevant to JEE Main
Diagrams and graphical representations for better understanding
Numerical problems and their step-by-step solutions
Previous years' JEE Main questions for real exam experience
Time management strategies while solving MCQs
Exam Relevance
The topics covered in JEE Main are not only significant for the JEE exam but also appear in various CBSE and State Board examinations. Many concepts are shared with the NEET syllabus, making them relevant across multiple competitive exams. Common question patterns include conceptual applications, numerical problems, and theoretical questions that assess a student's understanding of core subjects.
Common Mistakes Students Make
Misinterpreting the question stem, leading to incorrect answers
Neglecting units in numerical problems, which can change the outcome
Overlooking negative marking and not managing time effectively
Relying too heavily on rote memorization instead of understanding concepts
Failing to review and analyze mistakes from practice tests
FAQs
Question: How can I improve my speed in solving JEE Main MCQ questions?Answer: Regular practice with timed quizzes and focusing on shortcuts can significantly enhance your speed.
Question: Are the JEE Main objective questions similar to previous years' papers?Answer: Yes, many questions are based on previous years' patterns, so practicing them can be beneficial.
Question: What is the best way to approach JEE Main practice questions?Answer: Start with understanding the concepts, then attempt practice questions, and finally review your answers to learn from mistakes.
Now is the time to take charge of your preparation! Dive into solving JEE Main MCQs and practice questions to test your understanding and boost your confidence for the exam.
Q. What is the enthalpy change for the reaction 2Na + Cl2 → 2NaCl?
A.
-411 kJ
B.
-240 kJ
C.
0 kJ
D.
411 kJ
Show solution
Solution
The enthalpy change for the formation of NaCl from its elements is -411 kJ.
Correct Answer:
A
— -411 kJ
Learn More →
Q. What is the enthalpy change for the reaction at constant pressure?
A.
ΔH = ΔU + PΔV
B.
ΔH = ΔU - PΔV
C.
ΔH = ΔU + VΔP
D.
ΔH = ΔU - VΔP
Show solution
Solution
At constant pressure, the enthalpy change is given by ΔH = ΔU + PΔV.
Correct Answer:
A
— ΔH = ΔU + PΔV
Learn More →
Q. What is the enthalpy change for the reaction N2(g) + 3H2(g) → 2NH3(g) at standard conditions?
A.
-92.4 kJ
B.
-45.9 kJ
C.
0 kJ
D.
0.5 kJ
Show solution
Solution
The standard enthalpy change for the formation of ammonia is -92.4 kJ.
Correct Answer:
A
— -92.4 kJ
Learn More →
Q. What is the enthalpy change for the reaction: 2H2(g) + O2(g) → 2H2O(g)?
A.
It is positive.
B.
It is negative.
C.
It is zero.
D.
It is dependent on temperature.
Show solution
Solution
The formation of water from hydrogen and oxygen is an exothermic reaction, thus the enthalpy change is negative.
Correct Answer:
B
— It is negative.
Learn More →
Q. What is the enthalpy change for the reaction: 2H2(g) + O2(g) → 2H2O(l)?
A.
-571.6 kJ
B.
-285.8 kJ
C.
0 kJ
D.
285.8 kJ
Show solution
Solution
The enthalpy change for the formation of 2 moles of water is -571.6 kJ.
Correct Answer:
A
— -571.6 kJ
Learn More →
Q. What is the enthalpy change for the reaction: C(s) + O2(g) -> CO2(g)?
A.
-393.5 kJ/mol
B.
-241.8 kJ/mol
C.
0 kJ/mol
D.
285.8 kJ/mol
Show solution
Solution
The enthalpy change for the formation of CO2 from carbon and oxygen is -393.5 kJ/mol.
Correct Answer:
A
— -393.5 kJ/mol
Learn More →
Q. What is the enthalpy change for the reaction: C(s) + O2(g) → CO2(g)?
A.
-393.5 kJ/mol
B.
-241.8 kJ/mol
C.
0 kJ/mol
D.
285.8 kJ/mol
Show solution
Solution
The enthalpy change for the formation of CO2 from its elements is -393.5 kJ/mol.
Correct Answer:
A
— -393.5 kJ/mol
Learn More →
Q. What is the enthalpy change for the reaction: CaCO3(s) → CaO(s) + CO2(g)?
A.
It is an endothermic reaction.
B.
It is an exothermic reaction.
C.
It has no enthalpy change.
D.
It is spontaneous at all temperatures.
Show solution
Solution
The decomposition of calcium carbonate is an endothermic reaction, requiring heat input.
Correct Answer:
A
— It is an endothermic reaction.
Learn More →
Q. What is the enthalpy change for the reaction: H2(g) + 1/2 O2(g) → H2O(l)?
A.
-285.8 kJ/mol
B.
0 kJ/mol
C.
-241.8 kJ/mol
D.
-572 kJ/mol
Show solution
Solution
The standard enthalpy change for the formation of water from its elements is -241.8 kJ/mol.
Correct Answer:
C
— -241.8 kJ/mol
Learn More →
Q. What is the enthalpy change for the reaction: N2(g) + 3H2(g) → 2NH3(g)?
A.
It is always positive.
B.
It is always negative.
C.
It can be either positive or negative depending on conditions.
D.
It is zero.
Show solution
Solution
The formation of ammonia from nitrogen and hydrogen is an exothermic reaction, thus the enthalpy change is negative.
Correct Answer:
B
— It is always negative.
Learn More →
Q. What is the enthalpy change when 1 mole of NaCl is dissolved in water?
A.
-3.87 kJ
B.
0 kJ
C.
+3.87 kJ
D.
-7.0 kJ
Show solution
Solution
The enthalpy change when 1 mole of NaCl is dissolved in water is approximately -3.87 kJ.
Correct Answer:
A
— -3.87 kJ
Learn More →
Q. What is the enthalpy change when 1 mole of water vapor condenses to liquid water?
A.
It is positive.
B.
It is negative.
C.
It is zero.
D.
It is dependent on pressure.
Show solution
Solution
The condensation of water vapor to liquid water releases heat, making the enthalpy change negative.
Correct Answer:
B
— It is negative.
Learn More →
Q. What is the entropy change for a reversible isothermal expansion of an ideal gas?
A.
nR ln(Vf/Vi)
B.
0
C.
nR(Tf - Ti)
D.
nC ln(Vf/Vi)
Show solution
Solution
The entropy change for a reversible isothermal expansion of an ideal gas is ΔS = nR ln(Vf/Vi).
Correct Answer:
A
— nR ln(Vf/Vi)
Learn More →
Q. What is the entropy change for a reversible isothermal process?
A.
Zero
B.
nR ln(Vf/Vi)
C.
nR(Tf - Ti)
D.
nR ln(Tf/Ti)
Show solution
Solution
The entropy change for a reversible isothermal process is ΔS = nR ln(Vf/Vi).
Correct Answer:
B
— nR ln(Vf/Vi)
Learn More →
Q. What is the entropy change for a reversible process?
A.
Always positive
B.
Always negative
C.
Can be zero
D.
Depends on the path taken
Show solution
Solution
For a reversible process, the entropy change can be zero if the process is isothermal and reversible.
Correct Answer:
C
— Can be zero
Learn More →
Q. What is the entropy change for a system that undergoes a phase transition at constant temperature?
A.
ΔS = 0
B.
ΔS = Q/T
C.
ΔS = T/Q
D.
ΔS = Q + T
Show solution
Solution
During a phase transition at constant temperature, the change in entropy is given by ΔS = Q/T, where Q is the heat absorbed or released.
Correct Answer:
B
— ΔS = Q/T
Learn More →
Q. What is the entropy change for an ideal gas during an isothermal expansion?
A.
Zero
B.
nR ln(Vf/Vi)
C.
nC_v ln(Tf/Ti)
D.
nC_p ln(Tf/Ti)
Show solution
Solution
The entropy change for an ideal gas during an isothermal expansion is ΔS = nR ln(Vf/Vi).
Correct Answer:
B
— nR ln(Vf/Vi)
Learn More →
Q. What is the entropy change for the isothermal expansion of an ideal gas from volume V1 to V2 at temperature T?
A.
R ln(V2/V1)
B.
R (V2 - V1)/T
C.
0
D.
R (V1/V2)
Show solution
Solution
The entropy change for an isothermal expansion is given by ΔS = nR ln(V2/V1). For 1 mole, ΔS = R ln(V2/V1).
Correct Answer:
A
— R ln(V2/V1)
Learn More →
Q. What is the entropy change for the mixing of two ideal gases at constant temperature?
A.
0
B.
R ln(2)
C.
R ln(V1/V2)
D.
R ln(V1*V2)
Show solution
Solution
The entropy change for the mixing of two ideal gases at constant temperature is ΔS = nR ln(2) for equal moles of each gas.
Correct Answer:
B
— R ln(2)
Learn More →
Q. What is the entropy change when 1 mole of an ideal gas is heated at constant volume from temperature T1 to T2?
A.
R ln(T2/T1)
B.
R (T2 - T1)
C.
0
D.
R (T1/T2)
Show solution
Solution
The change in entropy at constant volume is given by ΔS = nC_v ln(T2/T1). For 1 mole, ΔS = R ln(T2/T1).
Correct Answer:
A
— R ln(T2/T1)
Learn More →
Q. What is the entropy change when 1 mole of an ideal gas is heated at constant volume?
A.
0
B.
R ln(T2/T1)
C.
R (T2 - T1)
D.
R (T1/T2)
Show solution
Solution
The change in entropy when heating an ideal gas at constant volume is given by ΔS = nC_v ln(T2/T1). For 1 mole, it simplifies to ΔS = R ln(T2/T1).
Correct Answer:
B
— R ln(T2/T1)
Learn More →
Q. What is the entropy change when 1 mole of ice at 0°C is converted to water at 0°C?
A.
0 J/K
B.
R ln(2)
C.
R
D.
Positive value
Show solution
Solution
The phase change from ice to water at 0°C involves an increase in disorder, thus resulting in a positive change in entropy.
Correct Answer:
D
— Positive value
Learn More →
Q. What is the entropy change when 2 moles of an ideal gas are compressed isothermally from volume V2 to V1?
A.
-R ln(V1/V2)
B.
R ln(V1/V2)
C.
0
D.
R (V2 - V1)
Show solution
Solution
The change in entropy for an isothermal compression is ΔS = nR ln(V1/V2). For 2 moles, ΔS = 2R ln(V1/V2), which is negative since V1 < V2.
Correct Answer:
A
— -R ln(V1/V2)
Learn More →
Q. What is the equation for the displacement of a damped harmonic oscillator?
A.
x(t) = A e^(-bt) cos(ωt)
B.
x(t) = A e^(bt) cos(ωt)
C.
x(t) = A cos(ωt)
D.
x(t) = A e^(-bt) sin(ωt)
Show solution
Solution
The displacement of a damped harmonic oscillator is given by x(t) = A e^(-bt) cos(ωt), where b is the damping coefficient.
Correct Answer:
A
— x(t) = A e^(-bt) cos(ωt)
Learn More →
Q. What is the equation of a circle with center at (-1, 2) and radius 4?
A.
(x + 1)² + (y - 2)² = 16
B.
(x - 1)² + (y + 2)² = 16
C.
(x + 1)² + (y + 2)² = 16
D.
(x - 1)² + (y - 2)² = 16
Show solution
Solution
Using the standard form, the equation is (x + 1)² + (y - 2)² = 4² = 16.
Correct Answer:
A
— (x + 1)² + (y - 2)² = 16
Learn More →
Q. What is the equation of a circle with center at (2, -3) and radius 5?
A.
(x - 2)² + (y + 3)² = 25
B.
(x + 2)² + (y - 3)² = 25
C.
(x - 2)² + (y - 3)² = 25
D.
(x + 2)² + (y + 3)² = 25
Show solution
Solution
The standard form of a circle's equation is (x - h)² + (y - k)² = r², where (h, k) is the center and r is the radius.
Correct Answer:
A
— (x - 2)² + (y + 3)² = 25
Learn More →
Q. What is the equation of a circle with center at (h, k) and radius r?
A.
(x - h)^2 + (y - k)^2 = r^2
B.
(x + h)^2 + (y + k)^2 = r^2
C.
(x - h)^2 - (y - k)^2 = r^2
D.
(x + h)^2 - (y + k)^2 = r^2
Show solution
Solution
The equation of a circle with center at (h, k) and radius r is (x - h)^2 + (y - k)^2 = r^2.
Correct Answer:
A
— (x - h)^2 + (y - k)^2 = r^2
Learn More →
Q. What is the equation of an ellipse with foci at (±c, 0) and vertices at (±a, 0)?
A.
x^2/a^2 + y^2/b^2 = 1
B.
y^2/a^2 + x^2/b^2 = 1
C.
x^2/b^2 + y^2/a^2 = 1
D.
y^2/b^2 + x^2/a^2 = 1
Show solution
Solution
The standard form of the equation of an ellipse with horizontal major axis is x^2/a^2 + y^2/b^2 = 1.
Correct Answer:
A
— x^2/a^2 + y^2/b^2 = 1
Learn More →
Q. What is the equation of motion for a damped harmonic oscillator?
A.
m d²x/dt² + b dx/dt + kx = 0
B.
m d²x/dt² + kx = 0
C.
m d²x/dt² + b dx/dt = 0
D.
m d²x/dt² + b dx/dt + kx = F(t)
Show solution
Solution
The equation of motion for a damped harmonic oscillator is m d²x/dt² + b dx/dt + kx = 0.
Correct Answer:
A
— m d²x/dt² + b dx/dt + kx = 0
Learn More →
Q. What is the equation of motion for a simple harmonic oscillator with amplitude A and angular frequency ω?
A.
x(t) = A cos(ωt)
B.
x(t) = A sin(ωt)
C.
x(t) = A e^(ωt)
D.
x(t) = A ωt
Show solution
Solution
The equation of motion for SHM is x(t) = A cos(ωt) or x(t) = A sin(ωt).
Correct Answer:
A
— x(t) = A cos(ωt)
Learn More →
Showing 6721 to 6750 of 10700 (357 Pages)
