Introduction:
An L filter is a type of passive filter that uses inductors (L) and capacitors (C) to filter out unwanted signals or noise from a power supply. It is commonly used in power electronics to reduce the ripple current in DC power supplies. Ripple current is the small fluctuation in the output current of a power supply, typically caused by the switching action of the power electronics. It is undesirable as it can cause instability and affect the performance of electronic devices.

Explanation:
The ripple current in an L filter is influenced by various factors, including the load, the value of the inductor (L), and the value of the capacitor (C). However, in the given options, the correct answer is option 'B', which states that the ripple current increases with a decrease in load. Let's understand why this is the case:

1. Load:
The load refers to the electrical load connected to the power supply. It can be a resistor, a motor, or any other electronic device that consumes power. In an L filter, as the load decreases, the ripple current increases. This is because the load resistance determines the amount of current flowing through the filter. A lower load resistance means a higher current flow, which leads to increased ripple current.

2. Inductor (L):
The inductor in an L filter plays a crucial role in reducing the ripple current. It stores energy during the high current periods and releases it during the low current periods, effectively smoothing out the current waveform. However, the value of the inductor (L) itself does not directly impact the ripple current. It primarily affects the cutoff frequency of the filter, which determines the frequency range over which the filter can attenuate the ripple.

3. Capacitor (C):
The capacitor in an L filter works in conjunction with the inductor to further reduce the ripple current. It acts as a storage element, storing energy during the low current periods and releasing it during the high current periods. The value of the capacitor (C) also affects the cutoff frequency of the filter. However, like the inductor, it does not directly impact the ripple current.

Conclusion:
In an L filter, the ripple current increases with a decrease in load. This is because a lower load resistance allows for a higher current flow through the filter, leading to increased ripple current. The value of the inductor (L) and capacitor (C) primarily affect the cutoff frequency of the filter, but do not directly impact the ripple current. It is important to design the L filter appropriately to ensure that the ripple current is minimized and does not affect the performance of electronic devices.