GATE 2021 BM – Question 62
A pacemaker has a 2.4 Ah battery and delivers rectangular 1.5 V pulses lasting 1 ms once each second into electrode–heart resistance 150 Ω. Neglect other current drain. Find battery life in years, nearest integer.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 27 to 28
Explanation
During a pulse, current=1.5/150=.01 A. Duty cycle is .001 s/1 s=.001, so mean current=.01×.001=10⁻⁵ A. Battery life=2.4/10⁻⁵=240000 hours. Dividing by 24×365 gives 27.397 years, rounded to 27 years. This is the idealized stated battery-charge model.