#conducting loop

Energy Stored in Inductor and Magnetic Energy

A conducting loop is placed in a magnetic field that remains constant in magnitude and direction. No emf is induced beca

**Magnetic energy density** u = B²/(2μ₀), for B=0.5 T, u=0.25/(2×4π×10⁻⁷)=0.25/(2.513×10⁻⁶)=99471 J/m³, large, but volume small, total energy moderate. Inductor stores energy in field, released when current interrupted causing spark. Emf is induced only when magnetic flux changes. A constant field with a stationary loop results in no flux change, hence no emf. Using Φ = B A cosθ, e = -N dΦ/dt = -N A dB/dt = B l v = N B A ω sinωt, L = μ₀ N²A/l, M = e/(dI/dt) and U = ½ L I², result No change in magnetic flux follows, reflecting Faraday's law and Lenz's opposition.

Ref: NCERT > Physics Book > Electromagnetic Induction > Energy Stored in Inductor and Magnetic Energy

View Details

Self-Induction and Self-Inductance

A conducting loop is compressed in a uniform magnetic field. The induced current flows to maintain what quantity against

**Self-inductance of solenoid** L = μ₀ N² A / l, N total turns, A cross-section, l length, for N=650 turns per meter means n=650 m⁻¹, if length 1 m N=650, A=0.014, L=4π×10⁻⁷×650²×0.014/1=0.00743 H, self-induced emf magnitude L |dI/dt|, dI/dt=12 A/s, e=0.089 V, opposes change. The current opposes the decrease in flux by maintaining the original flux direction, resisting the reduction in area per Lenz’s law. Using Φ = B A cosθ, e = -N dΦ/dt = -N A dB/dt = B l v = N B A ω sinωt, L = μ₀ N²A/l, M = e/(dI/dt) and U = ½ L I², result Magnetic flux

Ref: NCERT > Physics Book > Electromagnetic Induction > Self-Induction and Self-Inductance

View Details

Self-Induction and Self-Inductance

A conducting loop is twisted in a uniform magnetic field. The induced emf arises primarily from what change?

**Self-inductance of solenoid** L = μ₀ N² A / l, N total turns, A cross-section, l length, for N=650 turns per meter means n=650 m⁻¹, if length 1 m N=650, A=0.014, L=4π×10⁻⁷×650²×0.014/1=0.00743 H, self-induced emf magnitude L |dI/dt|, dI/dt=12 A/s, e=0.089 V, opposes change. Twisting changes the orientation of the loop’s area vector relative to the field, altering the magnetic flux and inducing an emf. Using Φ = B A cosθ, e = -N dΦ/dt = -N A dB/dt = B l v = N B A ω sinωt, L = μ₀ N²A/l, M = e/(dI/dt) and U = ½ L I², result Change in

Ref: NCERT > Physics Book > Electromagnetic Induction > Self-Induction and Self-Inductance

View Details

Magnetic Flux and Faraday's Laws of Induction

A conducting loop is moved out of a magnetic field region. The induced current flows to oppose what specific change?

**Flux change example** coil 150 turns area 0.06 m² B 0.14 T drops to zero in 0.3 s, ΔΦ = B A =0.14×0.06=0.0084 Wb per turn, ΔΦ/Δt=0.028 Wb/s, e=150×0.028=4.2 V, illustrating calculation from B and area. Moving the loop out reduces the magnetic flux through it, and the induced current opposes this decrease by generating a field in the same direction as the original field. Using Φ = B A cosθ, e = -N dΦ/dt = -N A dB/dt = B l v = N B A ω sinωt, L = μ₀ N²A/l, M = e/(dI/dt) and U = ½ L I², result Decrease in

Ref: NCERT > Physics Book > Electromagnetic Induction > Magnetic Flux and Faraday's Laws of Induction

View Details

Magnetic Flux and Faraday's Laws of Induction

A conducting loop is moved into a uniform magnetic field region. During the entry, the induced current flows in a direct

**Flux change example** coil 150 turns area 0.06 m² B 0.14 T drops to zero in 0.3 s, ΔΦ = B A =0.14×0.06=0.0084 Wb per turn, ΔΦ/Δt=0.028 Wb/s, e=150×0.028=4.2 V, illustrating calculation from B and area. The direction opposes the increase in flux as the loop enters, governed by Lenz’s law, which ensures the current resists the change. Using Φ = B A cosθ, e = -N dΦ/dt = -N A dB/dt = B l v = N B A ω sinωt, L = μ₀ N²A/l, M = e/(dI/dt) and U = ½ L I², result Lenz’s law follows, reflecting Faraday's law and Lenz's opposition.

Ref: NCERT > Physics Book > Electromagnetic Induction > Magnetic Flux and Faraday's Laws of Induction

View Details