\(R_{tđ}=\dfrac{R_1\cdot R_2}{R_1+R_2}=\dfrac{24\cdot12}{24+12}=8\Omega\)

\(I=\dfrac{U}{R}=\dfrac{12}{8}=1,5A\)

\(P=\dfrac{U^2}{R}=\dfrac{12^2}{8}=18W\)

\(Q_{tỏa1}=A_1=U_1\cdot I_1\cdot t=12\cdot\dfrac{12}{24}\cdot1\cdot3600=21600J\)

\(Q_{tỏa2}=A_2=U_2\cdot I_2\cdot t=12\cdot\dfrac{12}{12}\cdot1\cdot3600=43200J\)

k

10. B

11. C

-Thí nghiệm: Cho một ít KMnO4 hoặc KClO3 vào ống nghiệm có cắm ống dẫn khí,đầu ống nghiệm được nút lại.

Câu hỏi là: cách điều chế oxi trong phòng thí nghiệm á

Giúp mình đi mọi ngừi ơiii 😥🥺

Đề bài đâu rồi ạ, có đề mới giải được ạ

1. She asked Minh if / whether he could speak Spanish

2. ​Thanh asked her teacher if / whether she would finish her exercise at home

3. Nien asked Hoa if / whether she had many new friends

4. They asked us if / whether we had to go then

5.  They said to us if / whether we had to go then

6. I asked Nam if / whether he was free tonight

7. She asked me if / whether I knew the way to the station

8. John asked Nhi if / whether Phong Nha was in southern Vietnam

9. The visitors asked if / whether they could take photos 

10. Daniel asked Jim if / whether there was a cafe nearby

\(Errink \times Cream\)

1 D

2 C

3 A

4 C

5 B

1. D

2. C

3. A

4. B

5. B

1 of

2 after

3 on - in

4 between - and

5 on - of