Question

What is the purpose of a capacitor in a mobile phone?

Answer 1

Before answering our question, we need to understand the definition of a capacitor. A capacitor is an electronic device that stores electric charge in an electric field. It is a passive electronic component having two terminals meaning it can only receive energy and instead of generating power, it stores and dissipates power.

Complete step-by-step solution:
The main property of a capacitor is that it can store energy and dissipate this energy when needed. But the purpose of a capacitor in a mobile phone depends on the circuit in which it has been connected. Some important purposes of a capacitor inside a mobile phone are:
(i) A capacitor is used to suppress the mini voltage spikes inside the phone.
(ii) It helps keep the voltage constant when it is fluctuating up and down at times.
(iii) When the phone is almost about to discharge, the capacitor helps in providing a ‘boost’ power to the mobile phone for a short duration of time.
(iv) When the battery of a mobile phone is being charged, the capacitors in the phone maintain power supply to all the components.
(v) If a phone is disconnected from the charging port, the capacitor can dissipate its stored energy and can be used as a temporary battery for some time.
Hence, these are the main purpose of installing a capacitor in a mobile phone.

Note: A very innovative application of capacitor in modern phones is the invention of capacitive touch screen. It works on the fact that our body has some very minute charge, so when we touch the screen of our mobile phones, tiny circuits inside the phone sense this charge and perform the desired task.