As you can see in the script I made 2 plot commands. However, there is nothing shown on the graphs. The display results is accurate, but I would like to have the graphs shown.

% Solenoid parameters
plungerWeight = 2.43; % Plunger weight [g]
numTurns = 60; % Number of coil turns
current = 0.5; % Current [A]
time = 1; % Duration of solenoid being active [s]
plunger_mass = 2.43; % mass of plunger + spring [g]
L = 0.01; % Inductance [H]
R = 10; % Resistance [ohm]
K = 0.1; % Force constant [N/A]
r = 1.6; % radius of coil [mm]
V = 67.35; % Volume of solenoid [mm^3]

% Magnetic properties
l = V/(3.14*r^2) ; % coil length [mm]
permeability = 4*pi*1e-7; % Permeability of free space [H/m]
crossSectionalArea = (L*l)/(numTurns^2*permeability); % Cross-sectional area of the solenoid [m^2]

% Calculate the magnetic field strength
magneticField = (numTurns * current) / (crossSectionalArea * permeability);

% Calculate the force exerted by the solenoid
force = magneticField * plungerWeight;

% Calculate the displacement from speed
velocity = (force * time)/plunger_mass; % velocity of plunger upward movement [m/s]
displacement = velocity * time; % upward displacement of the plunger [mm]

% Plot the results
figure;
subplot(2, 1, 1);

plot1 = plot(t, force);

Unrecognized function or variable 't'.

xlabel('Time [s]');
ylabel('Current [A]');
title('Current vs Time');

subplot(2, 1, 2);
plot2 = plot(t, displacement);
xlabel('Time [s]');
ylabel('Displacement [m]');
title('Displacement vs Time');

% Display the results
disp(['Magnetic Field Strength: ', num2str(magneticField), ' T']);
disp(['Force Exerted by the Solenoid: ', num2str(force), ' N']);

Result

>> solenoid_sim

Magnetic Field Strength: 1289008.4633 T

Force Exerted by the Solenoid: 3132290.5657 N

[sadat golz]

Let me correct myself. The graphs are shown but no lines are visible. Plot command worked, however, the graphs do not show the lines.

[Dyuman Joshi]

Looking at the xlabel and titles, you need to use time instead of t.

[sadat golz]

thank you

Answer 1

[Cris LaPierre]

It is likely the variable you are plotting is a scalar (only has one value). In order to see a line, you must plot at least 2 points.

Try adding a marker style to your plot command to see if something appears. I've modified your plot commands to remove t, since it is not defined.

% Solenoid parameters
plungerWeight = 2.43; % Plunger weight [g]
numTurns = 60; % Number of coil turns
current = 0.5; % Current [A]
time = 1; % Duration of solenoid being active [s]
plunger_mass = 2.43; % mass of plunger + spring [g]
L = 0.01; % Inductance [H]
R = 10; % Resistance [ohm]
K = 0.1; % Force constant [N/A]
r = 1.6; % radius of coil [mm]
V = 67.35; % Volume of solenoid [mm^3]

% Magnetic properties
l = V/(3.14*r^2) ; % coil length [mm]
permeability = 4*pi*1e-7; % Permeability of free space [H/m]
crossSectionalArea = (L*l)/(numTurns^2*permeability); % Cross-sectional area of the solenoid [m^2]

% Calculate the magnetic field strength
magneticField = (numTurns * current) / (crossSectionalArea * permeability);

% Calculate the force exerted by the solenoid
force = magneticField * plungerWeight;

% Calculate the displacement from speed
velocity = (force * time)/plunger_mass; % velocity of plunger upward movement [m/s]
displacement = velocity * time; % upward displacement of the plunger [mm]

% Plot the results
figure;
subplot(2, 1, 1);
plot1 = plot(force,'-*');
xlabel('Time [s]');
ylabel('Current [A]');
title('Current vs Time');

subplot(2, 1, 2);
plot2 = plot(displacement,'-*');
xlabel('Time [s]');
ylabel('Displacement [m]');
title('Displacement vs Time');

% Display the results
disp(['Magnetic Field Strength: ', num2str(magneticField), ' T']);

Magnetic Field Strength: 1289008.4633 T

disp(['Force Exerted by the Solenoid: ', num2str(force), ' N']);

Force Exerted by the Solenoid: 3132290.5657 N

[sadat golz]

Thank you for your answer