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. A disk is rotating with an angular velocity of 10 rad/s. If it experiences a constant angular acceleration of 2 rad/s², what will be its angular velocity after 5 seconds?
A.
20 rad/s
B.
10 rad/s
C.
30 rad/s
D.
15 rad/s
Solution
Using the formula ω = ω₀ + αt, we have ω = 10 + 2*5 = 20 rad/s.
Q. A disk rolls without slipping on a horizontal surface. If its radius is R and it rolls with a linear speed v, what is the angular speed of the disk?
A.
v/R
B.
R/v
C.
vR
D.
v^2/R
Solution
The relationship between linear speed and angular speed for rolling without slipping is given by ω = v/R.
Q. A disk rotates about its axis with an angular velocity of ω. If its radius is doubled while keeping the mass constant, what will be the new angular momentum?
A.
2Iω
B.
4Iω
C.
Iω
D.
I(2ω)
Solution
The moment of inertia I of a disk is proportional to r^2, so if the radius is doubled, I becomes 4I. Thus, angular momentum L = Iω becomes 4Iω.
Q. A disk rotates about its axis with an angular velocity of ω. If its radius is doubled while keeping the mass constant, what will be the new moment of inertia?
A.
2I
B.
4I
C.
I
D.
I/2
Solution
The moment of inertia of a disk is I = (1/2)MR^2. If the radius is doubled, the new moment of inertia becomes I' = (1/2)M(2R)^2 = 4I.
Q. A disk rotates about its axis with an angular velocity of ω. If its radius is doubled, what will be the new angular momentum if the mass remains the same?
A.
2ω
B.
4ω
C.
ω
D.
ω/2
Solution
Angular momentum L = Iω. If the radius is doubled, the moment of inertia increases by a factor of 4, thus L = 4Iω.
Q. A disk rotates about its axis with an angular velocity of ω. If its radius is doubled, what will be the new angular velocity to maintain the same linear velocity at the edge?
A.
ω/2
B.
ω
C.
2ω
D.
4ω
Solution
The linear velocity v = rω. If the radius is doubled, to maintain the same v, the angular velocity must remain ω.
Q. A disk rotates about its axis with an angular velocity of ω. If its radius is doubled, what will be the new angular velocity to conserve angular momentum?
A.
ω
B.
2ω
C.
ω/2
D.
ω/4
Solution
To conserve angular momentum, if the radius is doubled, the angular velocity must be halved.
Q. A double convex lens has a focal length of 10 cm. If it is made of a material with a refractive index of 1.5, what is the radius of curvature of each surface assuming they are equal?
A.
15 cm
B.
20 cm
C.
25 cm
D.
30 cm
Solution
Using the lens maker's formula, R = 2f(n-1) = 2*10*(1.5-1) = 20 cm.
Q. A family has 2 children. What is the probability that both children are boys if it is known that at least one is a boy?
A.
1/2
B.
1/3
C.
1/4
D.
1/5
Solution
The possible combinations of children are BB, BG, GB, GG. Given that at least one is a boy, we can eliminate GG, leaving us with BB, BG, GB. Out of these 3 combinations, only 1 is BB. Therefore, the probability is 1/3.