Question

One company sells a defibrillator for home use that uses a 9-volt DC battery. The battery is rated at 4.2 A•hr (amp•hour). Roughly how much charge can the battery deliver?

A. 4.2 C
B. 38 C
C. 15,000 C
D. 136,000 C

Answer 1

The 9-volt DC battery rated at 4.2 A•hr can deliver approximately 15,000 C of charge, as calculated by multiplying the amp-hour rating by 3600 (the number of coulombs in an amp-hour).

Step-by-step explanation:

The 9-volt DC battery rated at 4.2 A•hr (amp•hour) can be used to calculate the total charge it can deliver. To find the charge (Q), which is measured in coulombs (C), we use the relationship Q = current (I) × time (T). Since 1 A•hr is equivalent to 3600 C (because 1 A = 1 C/s and there are 3600 seconds in an hour), we multiply the battery's amp-hour rating by 3600 to get the total charge in coulombs.

Q = 4.2 A•hr × 3600 C/hr = 15120 C

Therefore, the battery can deliver approximately 15,000 C of charge. Out of the options given, the closest to this value is option C, which is 15,000 C.