Burglar Alarm and Wind Turbine Quiz

What is the primary function of the PIR sensor in the burglar alarm system?

• It detects electrical signals from the environment.

• It detects heat (infrared radiation) emitted by moving human bodies.

• It generates high voltage directly to trigger an alarm.

• It converts sound waves into electrical impulses.

What role does the transistor play in the PIR alarm system?

• It amplifies the PIR sensor's heat detection.

• It acts as a switch that controls the flow of electrical current.

• It stores electrical energy for future use.

• It directly triggers the relay switch in Circuit 3.

Why does the circuit remain open when no signal is detected from the PIR sensor?

• The electromagnet does not receive power.

• The relay switch remains in a closed state.

• The transistor allows current to flow freely.

• The high-voltage battery in Circuit 3 is deactivated.

What happens when the PIR sensor detects an intruder?

• The transistor stops the flow of electricity.

• The signal is blocked, preventing the alarm from activating.

• The electromagnet is energized, closing the relay switch in Circuit 3.

• The alarm circuit is disconnected to avoid false alarms.

Why does the relay switch in Circuit 3 close when the electromagnet is activated?

• The electromagnet creates a strong magnetic field that pulls the relay switch.

• The transistor directly applies high voltage to the relay.

• The PIR sensor manually forces the relay to close.

• The circuit automatically shuts down, cutting off power to the alarm.

What would happen if the transistor in Circuit 2 failed to function properly?

• The PIR sensor would overheat and stop detecting motion.

• The circuit would always remain open, preventing the alarm from activating.

• The electromagnet would still work, but with reduced efficiency.

• The relay switch in Circuit 3 would close automatically, even without an intruder.

How does the wireless transmitter contribute to the overall alarm system?

• It wirelessly sends signals from the PIR sensor to the transistor.

• It ensures that the relay switch can operate without an electromagnet.

• It transmits an alarm signal to notify a security system remotely.

• It powers the PIR sensor using high voltage from Circuit 3.

Why does the system use both low voltage (Circuit 1 and 2) and high voltage (Circuit 3)?

• Low voltage is required for sensing and switching, while high voltage powers the alarm.

• Low voltage is safer for human interaction, and high voltage is used for faster processing.

• High voltage prevents false alarms, while low voltage stabilizes the system.

• Low voltage powers the alarm, while high voltage is used for minor electrical adjustments.

What would be the likely effect if the relay in Circuit 3 malfunctioned?

• The alarm would continuously stay on.

• The alarm would fail to activate even if the PIR sensor detects motion.

• The transistor would overheat and stop working.

• The wireless transmitter would operate in a loop, triggering false alarms.

What is the primary function of the low-speed shaft in a wind turbine?

• It directly drives the generator at 30-60 rpm.

• It rotates the high-speed shaft using a small gear.

• It transfers the initial rotational energy from the blades to the gearbox.

• It controls the speed of the wind turbine.