In closed loop, which of the following are directly (ie user) controlled?Question 3Select one:a.Duty cycleb.Output voltagec.Output currentd.Inductor voltage

In a closed loop system, the user directly controls the 'Output voltage'. So, the correct answer is option b. 'Output voltage'.

Here's why:

In a closed loop system, the output is constantly being measured and adjusted to maintain a desired value. This is done by feeding the output back into the system as an input. The user sets the desired output value, and the system adjusts itself to maintain this value.

In the context of a power supply (which is likely what this question is referring to), the user would set the desired output voltage, and the system would adjust the duty cycle, inductor voltage, and output current as necessary to maintain this voltage.

So, while the duty cycle, inductor voltage, and output current are all part of the system and will change based on the output voltage, they are not directly controlled by the user. They are controlled by the system itself in response to the user's desired output voltage.