\(\Rightarrow\dfrac{U1}{U2}=\dfrac{I1}{I2}\Rightarrow I2=\dfrac{U2.I1}{U1}=\dfrac{270.0,5}{220}=\dfrac{27}{44}A\)
\(\Rightarrow do-tang=I2-I1=\dfrac{27}{44}-0,5=\dfrac{5}{44}A\)
\(\dfrac{U}{U'}=\dfrac{I}{I'}\Rightarrow I'=\dfrac{U'\cdot I}{U}=\dfrac{\left(220+50\right)\cdot500}{220}=\dfrac{6750}{11}\left(mA\right)\)
\(\Delta I=I'-I=\dfrac{6750}{11}-500=\dfrac{1250}{11}\left(mA\right)\)