# Master the art of problem solving : Physics Demystified

## What you’ll learn

- learn the way to approach to any physics problem.
- Learn to solve physics in an intuitive way.
- Tackle any problem that you’ve never seen before.
- Learn complete ELECTROMAGNETISM AND GEOMETRICAL OPTICS.

## Requirements

- No prerequisites required.

## Description

- This course is gonna take you to a level you can’t think of from JEE ADVANCED point of view. All the concepts are explained from scratch and covers complete electromagnetism and ray optics from scratch. Everything is going to end in a 4 STAR problem which is highly relevant from Olympiad point of view.

**MAGNETIC EFFECTS OF CURRENT :** **Master the art of problem solving : Physics Demystified**

MODULE 1(C01): *What is BIOT’s SAVART law*? & Magnetic Field due to a finite current carrying wire subtending a particular angle at a perpendicular distance R.

MODULE 2(C02): *M.F on the axis of a Real solenoid & Extended BIOT SAVART’s Law* – M.F due to a current carrying coil on it’s axis, M.F of a square frame on it’s axis, currents formed by rotation of charges( M.F on the axis of a charge rotating disc), Inside and outside M.F lines of an ideal solenoid.

MODULE 3(C03): *AMPERE’s CIRCUITAL LAW *– Current flow in a thin cylindrical shell, M.F due to Rotation of positively charged annular cylinder, Excellent application of Ampere’s circuital law.

MODULE 4(C04): *AMPERIAN’S CORE* – M.F due to infinite current carrying hollow cylindrical shell, M.F due to infinite current carrying solid cylindrical core, M.F due to infinite cylindrical core with variable current density, M.F due to infinite cylindrical core inside an infinite cylindrical shell.

MODULE 5(C05): *VARIABLE M.F, THICK AND THINK INFINITE CURRENT CARRYING SHEETS* – M.F due to a cylindrical core with cavity.

MODULE 6(C06): *Introduction to Helix* – Motion of a charged particle in uniform magnetic field, 0,90 and acute angle between M.F and particle’s instantaneous velocity.

MODULE 7(C07): *COMPLEX MAGNETICS *– solving for the equation of particle governing the motion of particle using complex numbers ( polar and Euler’s form of complex numbers) and newton’s second law of motion

MODULE 8(C08): *BASIC DEVIATIONS* – Deviation of a charge under the influence of NON-UNIFORM M.F using Newton’s second law.

MODULE 9(C09) ({**}:* LORENTZ FORCE ON A SHORT WIRE *– Force(In vector form) on a *short* current carrying wire due to thin infinite current wire in NON-UNIFORM M.F in vector form.

Question covered: An infinitely long and thin wire carrying current I1 in the negative y direction lies along the y-axis (x = 0, z = 0). Another short and thin wire carrying current I2 in the positive x-direction lies parallel to the x-axis. Its two ends are at (0, 0, h) and (l, 0, h). Find the force on the short wire due to the long wire.

MODULE 10(C10){**}:* TRAVERSE E.F & M.F* – Motion of a charged particle in Lorentz force and finding *Trajectory* of the charged particle using the *concept of PURE ROLLING.*

MODULE 11(C11){***}: *COMPLEX MAGNETICS PART-II* – Finding the Instantaneous X , Y AND Z co-ordinates of the charged particle [*Solving FIRST ORDER LINEAR DIFFERENTIAL EQUATION*] under the influence of Lorentz force [ perpendicular E.F AND M.F ]

MODULE 12(C12){**}:* BENT WIRE* – M.F due to a thin infinitely current carrying wire bent at a point, Tension in a current carrying ring, Torque in M.F, Magnetic moment.

Question covered: An infinite wire is bent as shown in the figure below. Find the magnetic field at point P.

MODULE 13(C13){***}: *A CHARGE AND A WIRE* –

Question covered – A fixed infinite wire carries current I along the positive z-axis. Supposing that a charged particle of mass m and charge q is initially launched at a radial velocity v0 > 0 (positive outwards), at a perpendicular distance r0 from the wire, determine the maximum and minimum radial distances that the charged particle can attain from the wire.

**ELECTROMAGNETIC INDUCTION :**

MODULE 14(C14): *EMI Basics* – Introduction to Magnetic flux, Faraday’s Laws of EMI, Lenz law(based on energy conservation), Motional EMF, Induced EMF in a rotating rod with constant angular velocity, EMF induced in a rotating rod without the presence of any external M.F.

***first 4 circuits are of JEE MAINS level***

CIRCUIT 1: Find the potential difference across conducting rod AB. Internal resistance = r

CIRCUIT 2: Find the instantaneous current induced in the moving loop at a constant speed u. Internal resistance of the loop = 4R.

CIRCUIT 3: Find the external force and power required to maintain constant speed of the conducting rod of length L.

CIRCUIT 4: A rectangular loop of dimensions l and h moves with a constant velocity u away from a long wire that carries a steady current I1 in the plane of the loop. The total resistance of the loop is R. Derive an expression for the current I2 in the loop at the instant the closer side of the loop is a distance r from the wire. We have done a similar problem before but use the flux rule this time. Notice that the resistor heats up. What is providing this energy or rather, doing work on the system? The magnetic force seems to be doing work! Resolve this apparent paradox.

***5 to 8 are relevant for ADV.**(INTERMEDIATE EMI)*

CIRCUIT 5: Find the speed of conducting rod sliding on infinite smooth frictionless rails as a function of time. Initial speed = u, uniform M.F = B(-k cap), internal resistance of rod = r.

CIRCUIT 6: In circuit 5, Find the terminal speed of the rod if a constant force= F acts on it throughout its motion. initial speed = 0.

CIRCUIT 7: Find the charge on capacitor as a function of time.

CIRCUIT 8: A square loop is exiting a constant and uniform magnetic field B with a constant velocity v perpendicular to the magnetic field. Find the emf induced in the loop when the left end of the loop is at a distance x from the right boundary of the magnetic field. Find the force required to maintain the velocity of the loop. The loop has resistance R and negligible self-inductance.

CIRCUIT 9: *ROTATING RING* – A ring with mass m, radius r and resistance R is rotating about a diameter in a region of constant and uniform external magnetic field B. Initially, the magnetic field passes through the ring perpendicularly, resulting in maximum flux through the ring, and the ring rotates with initial angular speed ω0. Neglect the self-inductance of the ring.

(a) Find the relation between the total angle φ that the ring rotates before it stops, and the other given variables.

(b) Find the number of complete rounds that the ring manages to rotate when it initially spins at 8 rotations per second, m = 1kg, R = 1Ω, r = 30cm, and B = 1T.

CIRCUIT 10: NORMAL DC CIRCUIT WITH INCORPORATED EMI

MODULE 15(C15): *EMI THEORY* – Induced E.F due to time varying M.F, Emf induced in a rotating rod *without the presence of any EXTERNAL MAGNETIC FIELD.*

## Who this course is for:

- Anyone targeting JEE ADVANCED or OLYMPIADS.