MCAT Physics Question 85: Answer and Explanation
Home > MCAT Test > MCAT physics practice tests
Test Information
- Use your browser's back button to return to your test results.
- Do more MCAT physics practice tests.
Question: 85
10. The energy stored in a fully charged capacitor is given by . In a typical cardiac defibrillator, a capacitor charged to 7500 V has a stored energy of 400 J. Based on this information, what is the charge on the capacitor in the cardiac defibrillator?
- A. 1.1 × 10-5 C
- B. 5 × 10-2 C
- C. 1.1 × 10-1 C?
- D. 3.1 × 106 C
Correct Answer: C
Explanation:
Because the question is asking us to calculate the charge on the capacitor, use the formula Q = CV. We are given V = 7500 V and can calculate C from the formula for energy,
:
Thus, the charge is close to 0.1 C, which is closest to choice (C).