zad.2. t = 2 s n = 12 * 10¹⁹ e = 1,602 *10 ⁻¹² C q = n *e q = 12 * 10¹⁹ * 1,602 *10 ⁻¹⁹ C q = 19,3 C U = 80 V R = ? R = U / I I = q / t R = U * t /q R = 80 V * 2 s / 19,3 C R ≈ 8,3 Ω zad.3. ρ₁ miedzi = 1,7 *10⁻⁸ Ω * m ρ₂ platyny = 0,11 *10⁻⁶ Ω * m l₁ = l₂ = l S₁ = S₂ = S R₁ / R₂ = ? R = ρ * l / S R₁ = ρ₁ * l / S R₂ = ρ₂ * l / S R₁ / R₂ = ρ₁ * l / S / S / ρ₂ * l R₁ / R₂ = ρ₁ / ρ₂ R₁ / R₂ = 1,7 *10⁻⁸Ω * m / 0,11 *10⁻⁶ Ω * m R₁ / R₂ ≈ 15,5 *10⁻² zad.3 R₁ = 20 Ω R₂ = 12 Ω I = 10 A I₁ , I₂ = ? 1. obliczam Rz ( połączenie równoeległe ) 1 / Rz = 1 /R₁ + 1/ R₂ 1/ Rz = 1/ 20 + 1/12 1/Rz = 3 /60 + 5 / 60 1/Rz = 8 / 60 Rz = 60 / 8 Ω = 7,5 Ω 2. obl. U U = Rz * I U = 7,5 Ω * 10 A ; [Ω ] = = [ V / A ] U = 75 V 3. obl. I I₁ = U / R₁ I₁ = 75 V / 20 Ω I₁ = 3,75 A I₂ = U / R₂ I₂ = 75 V / 12 Ω I₂ = 6,25 A spr; I = I₁ + I₂ I = 3,75 A + 6,25 A I = 10 A
