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As the CBSE Class 12 board exams get closer, it’s important for students to understand the new exam pattern. Starting in the 2024-25 school year, CBSE will include 50% more competency-based questions. These questions will be both multiple choice and written, focusing on how to use what students have learned in real-life situations.
For Class 12 Physics, Unit -4 on Electromagnetic Induction and Alternating Current (AC), CBSE has provided competency-based questions that help improve understanding and application skills. It highlights key competency-based questions and provides answers to help students succeed. These questions are designed to help students strengthen their understanding and apply concepts effectively for their exams.
By practicing these competency-based questions, students will get familiar with the types of questions they are likely to face in the exam. The free PDF includes a variety of questions, such as multiple-choice (MCQs) and free-response questions, with answers provided to guide students in their preparation.
CBSE Class 12 Physics Chapter 4: Electromagnetic Induction and Alternating Current (AC) Important Competency-Based Questions
Q.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)?
A. 0.7
B. 1
C. 1.42
D. 7
Answer. C. 1.42
Q.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?
A. (i) > (iii) > (iv) > (ii)
B. (iv) > (iii) > (i) > (ii)
C. (ii) > (iv) > (iii) > (i)
D. (iii) > (i) > (ii) > (iv)
Answer. A. (i) > (iii) > (iv) > (ii)
| Download PDF | |
| CBSE Class 12 Physics Unit 1 Electrostatics : Important Competency-Based Questions 2024-25 | Click Here |
| CBSE Class 12 Physics Unit 2 Current Electricity : Important Competency-Based Questions 2024-25 | Click Here |
| CBSE Class 12 Physics Unit 3 Magnetic Effect of Current and Electricity : Important Competency-Based Questions 2024-25 | Click Here |
| CBSE Class 12 Physics Unit 4 Electromagnetic Induction and Alternating Current (AC) : Important Competency-Based Questions 2024-25 | Click Here |
Q.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?
Answer.
Q.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?
A. 1/R1 2
B. R1 2
C. 1/R1
D. R1
Answer. D. R1
Q.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?
Answer.
Q.6 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?
A. π/4
B. 0.002
C. 0.008/π
D. 0.0005π
Answer. C. 0.008/π
Q.7 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?
A. Pav = 0 & iav > 0
B. Pav > 0 & iav = 0
C. Pav > 0 & iav > 0
D. Pav = 0 & iav = 0
Answer. B. Pav > 0 & iav = 0
Q.8 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.
A. Only statement IV is correct
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👉 Read Also - CBSE Class 12 Half-Yearly/Mid Term 2024-25 : Most Important Questions with Answers; PDF Download (All Subjects)
👉 Read Also - How CBSE’s New Exam Pattern Will Impact Class 11 and 12 Students
👉 CBSE Class 12 Study Materials
| CBSE Class 12 Syllabus 2024-25 | CBSE Class 12 Previous Year Papers |
| NCERT Books For Class 12 Books | NCERT Class 12 Solutions |
| CBSE Class 12 Full Study Material | CBSE Class 12 Sample Paper 2024-25 |
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