HOC24
Lớp học
Môn học
Chủ đề / Chương
Bài học
1. was waiting - came
2. rang - was watching
3. began - was sitting
4. was having - arrived
5. was listening - was reading
6. had - was repaired
7. was taking - went
8. was looking - found
9. was watching - rang
10. were - doing
Vôn kế mắc song song với R1 có tác dụng đo HĐT R1
=> HĐT giữa 2 đầu R1 là U1
Vôn kế mắc song song với R2 có tác dụng đo HĐT R
=> HĐT giữa 2 đầu R2 là U2
R1 nt R2 <=> I1=I2 (1)
Mà theo định luật Ôm:
I1=\(\dfrac{U1}{R1}\) ; I2=\(\dfrac{U2}{R2}\) (2)
Từ (1) và (2) ta có: \(\dfrac{U1}{R1}\) = \(\dfrac{U2}{R2}\)
<=> \(\dfrac{U1}{U2}\) = \(\dfrac{R1}{R2}\)
b,