How should the student change the circuit to give negative values for current and potential difference?

The student can reverse the direction of current flow in a circuit to obtain the negative values for current and potential difference in the circuit.

To determine the negative current flow and potential difference in a circuit, we can consider following ways;

Thus, the negative values of current and potential difference is obtained by reversing the direction of current flow in a circuit.

Learn more about current and potential difference here:

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Please find the answer in the explanation.

Explanation:

How should the student change the circuit to give negative values for current and potential difference?

Positive and Negative current can be seen when charging and discharging a device or when powering a load.

Negative current can also be achieved when current is allowed to flow in other direction.

If the direction of the current is changed, the voltage will read negative. Changing of power or battery terminals can make voltmetre to read negative.

b would be the answer

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia