Consider mathrmI_1$\mathrm{I}_1$ and mathrmI_2$\mathrm{I}_2$ are the currents flowing simultaneously in two nearby coils 1 & 2, respectively. If mathrmL_1 =$\mathrm{L}_1 =$ self inductance of coil 1, mathrmM_12 =$\mathrm{M}_{12} =$ mutual inductance of coil 1 with respect to coil 2, then the value of induced emf in coil 1 will be [cite: 1, 2]
### Related Formula
phi_1 = L_1 I_1 + M_12 I_2$\phi_1 = L_1 I_1 + M_{12} I_2$varepsilon_1 = -fracmathrmdphi_1mathrmdt$\varepsilon_1 = -\frac{\mathrm{d}\phi_1}{\mathrm{d}t}$
### Core Logic
The total flux linked with coil 1 is due to its own current I_1$I_1$ and the mutual influence of current I_2$I_2$ in the neighboring coil [cite: 2, 608]:
phi_1 = L_1 I_1 + M_12 I_2$\phi_1 = L_1 I_1 + M_{12} I_2$
Differentiating with respect to time according to Faraday\'s Law yields :
varepsilon_1 = -L_1 fracmathrmdI_1mathrmdt - M_12 fracmathrmdI_2mathrmdt$\varepsilon_1 = -L_1 \frac{\mathrm{d}I_1}{\mathrm{d}t} - M_{12} \frac{\mathrm{d}I_2}{\mathrm{d}t}$
### Pattern Recognition
Total induced emf sums both self-induction and mutual induction effects additively with standard Lenz law negative signs.
### Chapter Mix
Class 12 Physics: Electromagnetic Induction
Keywords:#induced emf in coil 1#JEE Main 2025 Morning Q7#self and mutual inductance#Faraday law flux induction
More Electromagnetic Induction Previous-Year Questions — Page 2
Q122025AC Generator
A coil of area A and N turns is rotating with angular velocity omega$\omega$ in a uniform magnetic field vecB$\vec{B}$ about an axis perpendicular to vecB$\vec{B}$ . Magnetic flux varphi$\varphi$ and induced emf varepsilon$\varepsilon$ across it, at an instant when vecB$\vec{B}$ is parallel to the plane of coil, are: [cite: 1, 2]
### Related Formula
phi = BAN cos(omega t)$\phi = BAN \cos(\omega t)$varepsilon = BANomega sin(omega t)$\varepsilon = BAN\omega \sin(\omega t)$
### Core Logic
AC Generator explanation diagram for Q12
When the magnetic field vector vecB$\vec{B}$ lines up parallel to the plane of the coil, the norm area vector stands perpendicular to vecB$\vec{B}$, yielding omega t = fracpi2$\omega t = \frac{\pi}{2}$. Thus :
phi = BAN cosleft(fracpi2right) = 0$\phi = BAN \cos\left(\frac{\pi}{2}\right) = 0$ [cite: 692, 693]
varepsilon = BANomega sinleft(fracpi2right) = NABomega$\varepsilon = BAN\omega \sin\left(\frac{\pi}{2}\right) = NAB\omega$
### Pattern Recognition
Flux is zero when the field lines are parallel to the coil surface, but the rate of change of flux (and thus emf) peaks to its absolute maximum[cite: 691, 693].
### Chapter Mix
Class 12 Physics: Electromagnetic Induction
More Electromagnetic Induction Questions — jee_main_2025_29_jan_morning
We Map Every Repeating Question in Competitive Exams.
Say goodbye to generic mock test fatigue. RankBit uses smart analysis to group past exam questions into their foundational Repeating Question Types. Find chapter weightage, track repeating questions, and score higher with targeted practice.
Select Your Target Exam
Choose an exam track below to find formulas per chapter and patterns.
Syncing Exam Intelligence
Mapping formulas and patterns across all tracks…
PATH A — FULL LENGTH PRACTICE
Full Mock Test Hub
Simulate real NTA exam conditions with fully tracked mocks. Time yourself against past papers.
Under Development
PATH B — TARGETED PRACTICE
Topic-wise Practice Hub
Practice past-year questions one chapter at a time. Pick an exam → subject → chapter and get every PYQ for that topic — pulled together from all past papers — with the chapter's key formulas alongside.
