Creating a new model in Simulink - Practice Exercises

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the first step to create a new model in Simulink?

You want to start a new simulation project in Simulink. What should you do first?

A Save an existing model under a new name without opening Simulink.

B Write MATLAB code to define the model before opening Simulink.

C Open Simulink and select 'Blank Model' from the start page.

D Open Simulink and immediately run the simulation without adding blocks.

💡 Hint

Think about how you start fresh in Simulink.

To create a new model, you open Simulink and choose 'Blank Model' to start building your system.

❓ Predict Output

intermediate

What is the output after creating and saving a new model named 'test_model'?

You run this MATLAB command sequence: open_system(new_system('test_model')); save_system('test_model'); close_system('test_model'); What is the result?

Simulink

open_system(new_system('test_model'));
save_system('test_model');
close_system('test_model');

A A new Simulink model file named 'test_model.slx' is saved in the current folder.

B An error occurs because 'new_system' cannot create a model.

C The model opens but is not saved to disk.

D The model is saved but remains open in Simulink.

💡 Hint

Check what 'save_system' does after creating a new model.

'new_system' creates a new model, 'save_system' saves it as a .slx file, and 'close_system' closes it.

❓ data_output

advanced

How many blocks are in a new blank Simulink model immediately after creation?

You create a new blank model in Simulink using the GUI or command line. How many blocks does it contain before adding anything?

A Three blocks: 'In1', 'Out1', and 'Scope'

B One default block named 'In1'

C Two blocks: 'In1' and 'Out1'

D Zero blocks

💡 Hint

Think about what a blank model means.

A new blank model starts empty with no blocks until you add them.

🔧 Debug

advanced

Why does this code fail to create a new model named 'myModel'?

Consider this MATLAB code: new_system('myModel') save_system('myModel') close_system('myModel') It raises an error at 'save_system'. What is the cause?

Simulink

new_system('myModel')
save_system('myModel')
close_system('myModel')

A The model was created but not opened, so 'save_system' cannot save it.

B The 'new_system' command needs a second argument to open the model.

C The model name 'myModel' is invalid and causes an error.

D The 'close_system' command must be called before 'save_system'.

💡 Hint

Check if the model is open before saving.

'new_system' creates the model but does not open it. 'save_system' requires the model to be open to save it.

🚀 Application

expert

Which command sequence correctly creates, opens, adds a Gain block, saves, and closes a new model?

You want to automate creating a new Simulink model named 'autoModel', add a Gain block, save, and close it. Which option does this correctly?

A new_system('autoModel'); open_system('autoModel'); add_block('simulink/Math Operations/Gain','autoModel/Gain'); save_system('autoModel'); close_system('autoModel');

B open_system(new_system('autoModel')); add_block('simulink/Math Operations/Gain','autoModel/Gain'); save_system('autoModel'); close_system('autoModel');

C new_system('autoModel'); add_block('simulink/Math Operations/Gain','autoModel/Gain'); save_system('autoModel'); close_system('autoModel');

D open_system('autoModel'); add_block('simulink/Math Operations/Gain','autoModel/Gain'); save_system('autoModel'); close_system('autoModel');

💡 Hint

Remember that 'new_system' returns the model name but does not open it automatically.

Option B creates and opens the model in one step, then adds the block, saves, and closes correctly.

Practice

1. What is the first step to create a new model in Simulink?

easy

A. Use new_system to create a new model.

B. Use simulink.open_system to open an existing model.

C. Add blocks directly without creating a model.

D. Save the model before creating it.

Solution

1. Step 1: Understand model creation functions

   The function new_system is used to create a new empty model in Simulink.

2. Step 2: Differentiate from opening models

   open_system opens existing models but does not create new ones.

3. Final Answer:

   Use new_system to create a new model. -> Option A

4. Quick Check:

   New model creation = new_system [OK]

Hint: Remember: new_system creates, open_system opens [OK]

Common Mistakes:

• Confusing new_system with open_system
• Trying to add blocks before creating a model
• Assuming saving creates a model

2. Which of the following is the correct syntax to create and open a new Simulink model named 'myModel'?

easy

A. simulink.create_system('myModel'); simulink.show_system('myModel');

B. simulink.open_system('myModel'); simulink.new_system('myModel');

C. new_system('myModel'); open_system('myModel');

D. simulink.new_system('myModel'); simulink.open_system('myModel');

Solution

1. Step 1: Identify correct function names

   The correct functions are new_system to create and open_system to open the model.

2. Step 2: Check function order and syntax

   Create the model first, then open it. new_system('myModel'); open_system('myModel'); follows this order and uses correct function names and syntax.

3. Final Answer:

   new_system('myModel'); open_system('myModel'); -> Option C

4. Quick Check:

   Create then open = new_system('myModel'); open_system('myModel'); [OK]

Hint: Create first, then open with correct function names [OK]

Common Mistakes:

• Using open_system before new_system
• Using incorrect function names like create_system
• Using incorrect 'simulink.' prefix

3. What will be the output of the following code snippet?

modelName = 'testModel';
new_system(modelName);
open_system(modelName);
blocks = find_system(modelName, 'Type', 'Block');
numBlocks = length(blocks);

What is the value of numBlocks right after running this code?

medium

A. 0

B. 1

C. An error occurs because the model is empty

D. Undefined variable error

Solution

1. Step 1: Understand model creation and block count

   After creating and opening a new model, it contains no blocks by default.

2. Step 2: Use find_system to count blocks

   find_system with 'Type'='Block' returns all blocks. Since none are added, the list is empty, so length is 0.

3. Final Answer:

   0 -> Option A

4. Quick Check:

   New model has zero blocks [OK]

Hint: New model starts empty, so block count is zero [OK]

Common Mistakes:

• Assuming default blocks exist
• Expecting an error for empty model
• Confusing blocks with system components

4. Consider this code snippet:

open_system('newModel');
new_system('newModel');

What is the main issue with this code when creating a new model?

medium

A. There is no issue; this code works fine.

B. The model is created twice, wasting memory.

C. The model name is invalid for Simulink.

D. The model is opened before it is created, causing an error.

Solution

1. Step 1: Analyze function order

   The code tries to open a model named 'newModel' before creating it, which causes an error because the model does not exist yet.

2. Step 2: Understand correct sequence

   The correct sequence is to create the model first with new_system, then open it.

3. Final Answer:

   The model is opened before it is created, causing an error. -> Option D

4. Quick Check:

   Open before create causes error [OK]

Hint: Always create before opening a model [OK]

Common Mistakes:

• Opening a model before creation
• Assuming open_system creates the model
• Ignoring error messages

5. You want to programmatically create a new Simulink model named 'controlSystem', add a Gain block, and open the model for editing. Which sequence of commands correctly achieves this?

hard

A. simulink.open_system('controlSystem'); add_block('simulink/Commonly Used Blocks/Gain', 'controlSystem/Gain1'); simulink.new_system('controlSystem');

B. new_system('controlSystem'); add_block('simulink/Commonly Used Blocks/Gain', 'controlSystem/Gain1'); open_system('controlSystem');

C. add_block('simulink/Commonly Used Blocks/Gain', 'controlSystem/Gain1'); simulink.new_system('controlSystem'); simulink.open_system('controlSystem');

D. simulink.new_system('controlSystem'); simulink.open_system('controlSystem'); add_block('simulink/Commonly Used Blocks/Gain', 'controlSystem/Gain1');

Solution

1. Step 1: Create the new model first

   Use new_system('controlSystem') to create the model before adding blocks.

2. Step 2: Add the Gain block to the model

   Use add_block with the correct source and destination path inside the new model.

3. Step 3: Open the model for editing

   Finally, open the model window with open_system('controlSystem') to see and edit it visually.

4. Final Answer:

   new_system('controlSystem'); add_block('simulink/Commonly Used Blocks/Gain', 'controlSystem/Gain1'); open_system('controlSystem'); -> Option B

5. Quick Check:

   Create, add block, then open model [OK]

Hint: Create model, add blocks, then open model [OK]

Common Mistakes:

• Adding blocks before creating the model
• Opening model before adding blocks
• Incorrect block path in add_block