Exercise 4.4 A

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the electromotive force (emf) of the unloaded battery and short-circuit current.

Tip: Move results to the (I, U) coordinate system, $U=E-R_{s}I$
Answer: The emf of the unloaded battery is 1,48 V and short-circuit current is 3,67 A

Exercise 4.4 B

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the electromotive force (emf) of the unloaded battery and short-circuit current.

Move results to the (I, U) -coordinate system, $U=E-R_{s}I$
Answer: $E=1,58 V$
$I_{short-circuit}=6,28 A$

Exercise 4.5 A

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

How many rounds are there in the transformer coil?

Tip: An unknown coil is connected to the secondary side.
Answer: 330

Exercise 4.5 B

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

How much does the measured secondary voltage differ (in volts and percentage) from the predicted secondary voltage of the ideal transformer?

Answer: 0,15 V; 4,6 %

Exercise 4.5 C

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

In the video you see transformers in use. How many rounds (turns) are there in the fourth coil?

Answer: 32

Exercise 4.6 A

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the threshold voltage of the diode and the resistance of the front resistor.

Answer: $0{,}75\ V$ ; $33\ \Omega$

Exercise 4.7 A

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the impedance of the circuit and the peak value of the voltage.

Answer: $26\ \Omega$ ; $3{,}3\ V$

Exercise 4.7 B

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the impedance of the circuit.

Tip: Place the measurement results in the (I, U) coordinate system.
Answer: $32\ \Omega$

Exercise 4.8 A

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the capacitance of the capacitor.

Tip: $Q = \int I(t) dt $
Answer: $980\ \mu F$ - $1100\ \mu F$

Exercise 4.8 B

Difficulty Secondary School High school/other
★ Basic Easy
★★ Demanding Basic
★★★ Demanding
★★★★ Difficult
★★★★★ Very difficult

Determine the capacitance of the capacitor and the phase between the voltage and the electric current.

Answer: $210\ \mu F$ ; $-56°$