To solve the problem of finding the source voltage when two capacitors are connected in series, we need to consider both their capacitance values and their breakdown voltages. In this case, we have a 3 microfarad (3C) capacitor and a 2 microfarad (2C) capacitor, with breakdown voltages of 1 kV and 2 kV, respectively. Let's break down the steps to find the total source voltage.
Understanding Series Capacitors
When capacitors are connected in series, the total capacitance (C_total) can be calculated using the formula:
For our capacitors:
- C1 = 3 microfarads (3C)
- C2 = 2 microfarads (2C)
Calculating Total Capacitance
Plugging in the values:
To combine these fractions, we need a common denominator, which is 6:
- 1/C_total = 2/6 + 3/6 = 5/6
Now, taking the reciprocal gives us:
- C_total = 6/5 microfarads = 1.2 microfarads
Determining Breakdown Voltage
The breakdown voltage of capacitors in series is the sum of their individual breakdown voltages. Therefore:
- V_breakdown_total = V1 + V2
Substituting the values:
Thus:
- V_breakdown_total = 1 kV + 2 kV = 3 kV
Calculating Source Voltage
The source voltage must not exceed the total breakdown voltage of the series combination of capacitors. Therefore, the maximum source voltage that can be applied without causing breakdown is:
- V_source = V_breakdown_total = 3 kV
Final Result
In conclusion, the source voltage that can be safely applied to the series combination of a 3 microfarad capacitor with a breakdown voltage of 1 kV and a 2 microfarad capacitor with a breakdown voltage of 2 kV is:
This ensures that neither capacitor exceeds its breakdown voltage, maintaining the integrity of the circuit.