Battery and power system in Drone Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the battery voltage variable.

Drone Programming

battery_voltage = [1]

Drag options to blanks, or click blank then click option'

A12.6

B'12.6V'

Cvoltage

Dbattery

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string instead of a number.

Using an undefined variable name.

The battery voltage should be a numeric value representing volts, so 12.6 is correct.

2fill in blank

medium

Complete the code to check if the battery voltage is below the warning level.

Drone Programming

if battery_voltage [1] 11.1:
    print('Warning: Low battery')

Drag options to blanks, or click blank then click option'

A>

B<

C==

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using greater than instead of less than.

Using equality operator which only checks exact match.

We want to warn if voltage is less than 11.1 volts, so the operator is <.

3fill in blank

hard

Fix the error in the code to calculate remaining battery percentage.

Drone Programming

remaining_percentage = (battery_voltage [1] 11.1) / (12.6 - 11.1) * 100

Drag options to blanks, or click blank then click option'

A/

B+

C-

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition instead of subtraction.

Using multiplication or division which changes the meaning.

We subtract 11.1 from battery_voltage to find how much voltage is left above the warning level.

4fill in blank

hard

Fill both blanks to create a dictionary of battery status for each cell.

Drone Programming

cell_status = {cell: voltage[1] for cell, voltage in battery_cells.items() if voltage [2] 3.7}

Drag options to blanks, or click blank then click option'

A- 3.7

B>

C<

D+ 3.7

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition instead of subtraction.

Using less than operator instead of greater than.

We subtract 3.7 to find voltage difference per cell and filter cells with voltage greater than 3.7.

5fill in blank

hard

Fill both blanks to create a dictionary of cells with voltage drop over threshold.

Drone Programming

voltage_drop = {cell: voltage[1] 3.7 for cell, voltage in battery_cells.items() if voltage[2] 3.5}

Drag options to blanks, or click blank then click option'

A:

B-

C>

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' instead of '-' for voltage difference.

Using '<' instead of '>' in filter condition.

Missing ':' between key and value.

Use ':' to map cell to voltage difference, subtract 3.7 to get drop, and filter cells with voltage greater than 3.5.

Practice

1. What is the main purpose of a battery in a drone?

easy

A. To send signals to the controller

B. To control the drone's speed

C. To store energy so the drone can fly

D. To cool down the drone's motors

Solution

1. Step 1: Understand the battery's role

   A battery stores electrical energy that powers the drone's motors and electronics.

2. Step 2: Compare options to battery function

   Only storing energy matches the battery's main purpose; other options describe different parts.

3. Final Answer:

   To store energy so the drone can fly -> Option C

4. Quick Check:

   Battery = Energy storage [OK]

Hint: Battery stores energy for flight power [OK]

Common Mistakes:

• Confusing battery with motor controller
• Thinking battery controls speed
• Mixing battery with communication parts

2. Which of the following is the correct way to check if the battery level is below 20% in drone code?

easy

A. if battery_level == '20%':

B. if battery_level < 20:

C. if battery_level > 20:

D. if battery_level = 20:

Solution

1. Step 1: Identify correct comparison operator

   To check if battery is below 20%, use less than operator: <.

2. Step 2: Check syntax correctness

   if battery_level < 20: uses correct syntax and operator; others use assignment (=), wrong comparison (>), or wrong type ('20%').

3. Final Answer:

   if battery_level < 20: -> Option B

4. Quick Check:

   Use < for less than check [OK]

Hint: Use '<' to check if battery is below threshold [OK]

Common Mistakes:

• Using '=' instead of '==' or '<'
• Comparing to string '20%'
• Using '>' instead of '<'

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

battery_level = 15
if battery_level < 20:
    print('Warning: Low battery')
else:
    print('Battery level OK')

medium

A. Battery level OK

B. No output

C. SyntaxError

D. Warning: Low battery

Solution

1. Step 1: Check battery_level value

   battery_level is 15, which is less than 20.

2. Step 2: Evaluate the if condition

   Since 15 < 20 is True, the code prints 'Warning: Low battery'.

3. Final Answer:

   Warning: Low battery -> Option D

4. Quick Check:

   15 < 20 triggers warning [OK]

Hint: Compare battery_level to 20 to decide output [OK]

Common Mistakes:

• Confusing output messages
• Thinking 15 is not less than 20
• Expecting syntax error

4. Identify the error in this drone battery check code:

if battery_level = 10:
    print('Battery low')

medium

A. Using '=' instead of '==' for comparison

B. Missing colon ':' after if statement

C. battery_level should be a string

D. print statement syntax is wrong

Solution

1. Step 1: Check the if statement syntax

   The code uses '=' which is assignment, not comparison.

2. Step 2: Correct comparison operator

   To compare, '==' must be used, so 'if battery_level == 10:' is correct.

3. Final Answer:

   Using '=' instead of '==' for comparison -> Option A

4. Quick Check:

   Use '==' to compare values [OK]

Hint: Use '==' to compare, not '=' [OK]

Common Mistakes:

• Using '=' in if condition
• Forgetting colon
• Wrong print syntax

5. You want to write a function that returns 'Safe to fly' if battery level is 30% or more, and 'Charge battery' otherwise. Which code correctly implements this?

hard

A. def check_battery(level):
if level >= 30:
return 'Safe to fly'
else:
return 'Charge battery'

B. def check_battery(level):
if level > 30:
return 'Charge battery'
else:
return 'Safe to fly'

C. def check_battery(level):
if level == 30:
return 'Safe to fly'
else:
return 'Charge battery'

D. def check_battery(level):
if level <= 30:
return 'Safe to fly'
else:
return 'Charge battery'

Solution

1. Step 1: Understand the condition for safe flight

   Safe to fly if battery level is 30% or more means level >= 30.

2. Step 2: Check each option's logic

   def check_battery(level): if level >= 30: return 'Safe to fly' else: return 'Charge battery' correctly returns 'Safe to fly' when level >= 30, else 'Charge battery'. Others reverse or misapply conditions.

3. Final Answer:

   def check_battery(level): if level >= 30: return 'Safe to fly' else: return 'Charge battery' -> Option A

4. Quick Check:

   Use >= 30 for safe flight check [OK]

Hint: Use '>=' to include 30% as safe [OK]

Common Mistakes:

• Using '>' instead of '>='
• Reversing return messages
• Checking only equality