A defibrillator is a device that provides a high energy electrical impulse to correct abnormal heart beats - Scottish Highers Physics - Question 11 - 2015

The maximum energy stored in the capacitor is given by:

$E = \frac{1}{2} C V^2$

Substituting the given values:

$E = \frac{1}{2} \times (64 \times 10^{-6} F) \times (2.50 \times 10^{3} V)^2$

Calculating this yields:

$E = 200 J$

Using Ohm's Law, we can derive the resistance:
$V = I imes R$
Rearranging gives:
$R = \frac{V}{I}$
Where V is the voltage across the paddles (2.50 kV = $2.50 imes 10^{3} V$) and I is the initial discharge current (35 A):
$R = \frac{2.50 \times 10^{3} V}{35 A} \approx 71.43 \Omega$

The current decreases with time due to the discharging of the capacitor. As the charge on the capacitor decreases while discharging through the person's body, the potential difference across the paddles also reduces, leading to a decrease in the current. Hence, even though the resistance remains constant, the current reduces because of the diminishing voltage.

The new line on the graph will start at a lower initial current than the first case due to the larger effective resistance of the person. This will result in a slower decrease towards zero. The curve is expected to decline more gradually compared to the original person owing to higher resistance.