Testing failsafe scenarios in Drone Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output when GPS signal is lost?

Consider this drone control snippet that triggers a failsafe when GPS signal is lost. What will be printed?

Drone Programming

def check_gps(signal_strength):
    if signal_strength < 20:
        print("Failsafe activated: Returning to home.")
    else:
        print("GPS signal stable.")

check_gps(15)

A Failsafe activated: Returning to home.

B GPS signal stable.

C Error: signal_strength undefined

D Failsafe activated: Landing immediately.

💡 Hint

Check the condition for signal strength less than 20.

The function prints the failsafe message when signal_strength is below 20. Since 15 < 20, it prints the failsafe message.

❓ Predict Output

intermediate

What happens if battery level is exactly at threshold?

This code triggers a failsafe if battery is below 15%. What will it print if battery is exactly 15%?

Drone Programming

def battery_check(level):
    if level < 15:
        print("Failsafe: Land immediately.")
    else:
        print("Battery level sufficient.")

battery_check(15)

A No output

B Failsafe: Land immediately.

C Battery level sufficient.

D Failsafe: Return to home.

💡 Hint

Check if the condition includes equality or only less than.

The condition is level < 15, so 15 is not less than 15. It prints the else branch.

❓ Predict Output

advanced

What error occurs if failsafe function is called without parameters?

What error will this code raise when calling failsafe() without arguments?

Drone Programming

def failsafe(mode):
    if mode == "return":
        print("Returning to home.")
    elif mode == "land":
        print("Landing immediately.")
    else:
        print("Unknown mode.")

failsafe()

A TypeError: failsafe() missing 1 required positional argument: 'mode'

B NameError: mode is not defined

C No output

D SyntaxError

💡 Hint

Check the function definition and how it is called.

The function requires one argument 'mode'. Calling it without arguments raises a TypeError.

🧠 Conceptual

advanced

Which condition triggers failsafe on sensor failure?

Given a sensor reading variable 'sensor_ok' that is True when sensors work and False when they fail, which condition correctly triggers the failsafe?

A

if sensor_ok = False:
    activate_failsafe()

B

if sensor_ok == False:
    activate_failsafe()

C

if sensor_ok != True:
    activate_failsafe()

D

if sensor_ok == True:
    activate_failsafe()

💡 Hint

Remember the difference between assignment and comparison.

Option B correctly compares sensor_ok to False using '=='. Option B uses assignment '=' which performs an assignment instead of a comparison. Option B also works logically but is less clear. Option B triggers failsafe when sensor is OK, which is wrong.

❓ Predict Output

expert

What is the output of the failsafe retry loop?

This code tries to reconnect up to 3 times. What will it print?

Drone Programming

def reconnect():
    for attempt in range(1, 4):
        print(f"Attempt {attempt}: Trying to reconnect...")
        if attempt == 2:
            print("Reconnected successfully.")
            break
    else:
        print("Failed to reconnect after 3 attempts.")

reconnect()

A

Attempt 1: Trying to reconnect...
Failed to reconnect after 3 attempts.

B

Attempt 1: Trying to reconnect...
Attempt 2: Trying to reconnect...
Attempt 3: Trying to reconnect...
Failed to reconnect after 3 attempts.

C Reconnected successfully.

D

Attempt 1: Trying to reconnect...
Attempt 2: Trying to reconnect...
Reconnected successfully.

💡 Hint

Check how the break affects the else clause of the loop.

The loop breaks on attempt 2 after printing success, so the else clause does not run.