Đáp án:

a) \({2.10^5}V\)

b) \({P_{h{p_2}}} = \dfrac{{100}}{9}{P_{h{p_1}}}\)

Giải thích các bước giải:

a) Ta có: 

\(\dfrac{{{U_1}}}{{{U_2}}} = \dfrac{{{N_1}}}{{{N_2}}} \Rightarrow \dfrac{{1500}}{{{U_2}}} = \dfrac{{300}}{{40000}} \Rightarrow {U_2} = {2.10^5}V\)

b) Ta có: 

\(\begin{array}{l}
\dfrac{{{P_{h{p_1}}}}}{{{P_{h{p_2}}}}} = {\left( {\dfrac{{{U_2}'}}{{{U_2}}}} \right)^2} = {\left( {\dfrac{{60000}}{{{{2.10}^5}}}} \right)^2} = \dfrac{9}{{100}}\\
 \Rightarrow {P_{h{p_2}}} = \dfrac{{100}}{9}{P_{h{p_1}}}
\end{array}\)