CBSE Class 12 Physics Competency-Based Questions With Answer Key 2024-25: Chapter 4 Electromagnetic Induction and Alternating Current (AC) FREE PDF Download

CBSE 2024-25 Competency-Based Questions With Answers: The Central Baord of Secondary Education has officially released the practice question paper for the academic year 2024-25, for the classes 10th  and 12th. Competency-focused questions can be helpful for students to secure good marks while referring and practicing them. It will help students to get familiar with the style and format of questions which are expected to appear in the final examinations.

The questions are designied chapter-wise for all the major subject of class 12th. In this article you will find specifically for Class 12 Physics Chapter 4  ELECTROMAGNETIC INDUCTION AND ALTERNATING CURRENT (AC), the CBSE Board has given the practice question paper for students to understand and up skill there preparation for 2025 examination. At the end of this article free PDF has been attached for the students to access and download. 

CBSE Class 12 Physics Chapter 4 Competency-Based Questions

Question 1: A current‐carrying coil C1 is paired with another coil. An emf ε is induced in coil C2 when the current through C1 drops to zero from a non‐zero value within 1 s. 

If the coil C1 is paired with C3, an emf 0.7ε is induced in it, for the same rate of 

drop in the current through C1 as earlier. 

What is the ratio of mutual inductance M12 (for the pair of coils C1 and C2) to 

that of mutual inductance M13 (for the pair of coils C1 and C3)? 

1. 0.7 
2. 1 
3. 1.42 
4. 7 

Question 2: Coil C carries a steady current. A second coil is placed in close proximity to coil  C in different configurations as shown. 

Which  of  the  following  options  represents  the  correct  order  of  the  mutual  inductance values for the pair of coils in given configurations? 

1. (i) > (iii) > (iv) > (ii) 
2. (iv) > (iii) > (i) > (ii) 
3. (ii) > (iv) > (iii) > (i) 
4. (iii) > (i) > (ii) > (iv) 

Question 3:  A long solenoid S has length l1, area of cross‐section A and number of turns N1.  A coil C of shorter length l2, number of turns N2 but same area of cross‐section  is wound over solenoid S. If a current I flows through the coil C, then which of  the following represents the flux linked with the solenoid S?  

Question 4:  There is a pair of concentric and coplanar conducting loops of radii R1 and R2 such that R2 = 0.01 R1. To  which  of  the  following  is  the  mutual  inductance  M  for  this  pair  directly proportional? 

1. 1/R₁²
2. R₁²
3. 1/R₁
4. R₁

Question 5:  A small conducting metal ring falls vertically down with its plane parallel to y‐z  plane. During the fall, the ring crosses a small region of the uniform magnetic  field directed along the x‐axis between the times t=0 and t = τ seconds.  Which of the following  graphs represent the variation of current induced in the  ring during the fall? 

Question 6: A capacitor is short‐circuited as shown.  

Match the possible motions listed in [A] of the bar magnet relative to the  loop with the suitable responses listed in [B] due to the induced current,  if any. 

1. [I ‐ i] , [II ‐ ii ], [III ‐ iii], [IV ‐ i ], [V ‐ ii] 
2. [I ‐ iii] , [II ‐ ii], [III – i], [IV – ii ], [V – i] 
3. [I ‐ii] , [II ‐ i], [III ‐ iii], [IV ‐ i], [V ‐ii] 
4. [I ‐ i] , [II ‐ ii], [III ‐ iii], [IV ‐ ii], [V ‐ i]

Question 7:  A square loop of a single turn is placed with its plane perpendicular to a uniform  magnetic field. The magnetic flux through the square loop is 0.002 Wb. The square loop is now reshaped into a circular loop. What is the flux (in Wb) through the circular loop? 

1. π/4 
2. 0.002 
3. 0.008/π 
4. 0.0005π 

Question 8: If  Pav  represents  average  power  dissipated  and  iav  is  the  average  current  through a resistor over one cycle of the input sinusoidal voltage, which of the following statements is correct for an ac circuit with resistor only? 

1. Pav = 0 & iav > 0 
2. Pav > 0 & iav = 0 
3. Pav > 0 & iav > 0 
4. Pav = 0 & iav = 0 

Question 9: An LCR series circuit is connected to an ac supply of ω = 100 rad/s. Given the values as R = 100‐ohm, L = 500 mH, C = 5 μF, study  the  following statements carefully. 

I. The given circuit (LCR) is dominantly capacitive 

II. The instantaneous current in the circuit leads Vmax. 

III. If w greater than 200√10 rad/s, the circuit becomes dominantly inductive 

IV. The LCR circuit can be made capacitive or inductive by simply changing the angular frequency of the input ac supply, keeping the voltage Vmax constant. Identify the correct option. 

1. Only statement IV is correct 
2. Only statements I and II are correct 
3. Only statements I and III are correct 
4. All statements are correct 

Question 10:  In an ac circuit containing a resistor R, the power dissipated is P1. If a capacitor C is added to the above circuit, the power dissipated through the resistor changes to P2. If  an  inductor  L  replaces  the  capacitor  C,  the  power  dissipated  through  the resistor changes to P3. If  the  capacitive  reactance  offered  by  the  capacitor  equals  the  inductive reactance offered by the inductor, then which of the following represents the correct relation between P1, P2 and P3? 

1. P1 = P2 = P3
2. P3 > P1 > P2
3. P1< [P2 = P3] 
4. P1 > [P2=P3] 

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To access all the practice question of Physics Chapter 4 Electromagnetic Induction and Alternating Current, the complete FREE PDFs are attached here. Click on the 'Download PDF' to get the PDF.

Tips To Prepare For Board Exam 

Preparing for board exams can be little challenging, but with right techniques and prepration you can approach your studies in the right direction. Here are some tips which will help you to prepare for board exams: 

• Make a Study Plan: Making study plan befor exam will beneficial for students. 
• Understand the Syllabus: Make sure you are familiarise your exam syllabus and ensure you cover all topics. 
• Use Study Materials: Use additional reference books and guides for more in-depth understanding if necessary.
• Practice Last Year Papers: Practice last year board exam sample papers to get a feel for the types of questions asked and the exam format. 
• Focus on conceptual understanding: Ensure you understand the concepts thoroughly.
• Regular Revision: Regularly revise what you've studied and make concise notes for quick revision of key points.

By following these tips, you can improve your preparation for board exams and increase your chances of achieving your desired results.

Related:

• CBSE 2025 Board Exam Dates

• CBSE Class 12 Syllabus 2024-25 (ALL SUBJECT PDFS)

• CBSE Class 12 Exam Pattern and Marking Scheme 2024-2025

Also Check:

• NCERT Books for CBSE Class 12 - Latest Edition

• NCERT Solutions for CBSE Class 12 - Updated

• NCERT Rationalised Content for Class 12

• Video Courses For CBSE Class 12 Science

• Video Courses For CBSE Class 12 Commerce

• Video Courses For CBSE Class 12 Humanities