1) Cho mach dien nhu hinh 2.6: U_AB = 18V, I₂ = 2A

a)  Tim R₂: R₁ = 5Ω, R₃ = 3Ω

1) tinh R₂

a) \(\dfrac{2R_2}{\left(\dfrac{3R_2}{3+R_2}\right)}\)

1) So 253125000 co bao nhieu uoc so tu nhien

1) Cho cac chu so: 0,1,2,3,4,5. Tu cac chu so da cho lap duoc bao nhieu so chan co 4 chu so khac nhau

1) Theo em khi bon phan cho cay trong, chung ta co the dua vao kinh nghiem cua nguoi nong dan qua nhung cau ca dao nao

1) Ong cha ta co cau: 

'' Trong troi, trong dat, trong may

Em hay giai thich cau noi tren

1) Cho mach dien nhu hinh 2.8:

Cho biet U_AB = 30V, cac dien tro giong nhau va co tri 6Ω. Tinh I mach chinh va I₆

1) Cho mach dien nhu hinh 2.7: 

R₁ = R₂ = 4Ω; R₃ = 6Ω; R₄ = 12Ω; R₅ = 0,6Ω; U_AB = 12V; R_A ≈ 0

a) Tinh R_AB

b) Tim I qua cac dien tro, va so chi cua Ampe ke

1) Cho mach dien nhu hinh 2.6: U_AB= 18V. I₂ = 2A

a) Tim R₁: R₂ = 6Ω; R₃ = 3Ω

b) Tim R₃: R₁ = 3Ω; R₂ = 1Ω

c) Tim R₂: R₁ = 5Ω; R₃ = 3Ω

1) Cho mach dien nhu hinh 2.5

Cho biet U_AB = 20V, R₁ = 2Ω; R₂ = 1Ω; R₃ = 6Ω; R₄ = 4Ω 

a) Tinh cuong do dong dien qua cac dien tro khi K mo

b) Tinh cuong do dong dien qua cac dien tro khi K dong va I qua K