Mobile Devices - Laptop Power Facts

Question 1

To save power, what can laptops do?

Answer 1

Turn off drives that aren’t currently being used.
Step down the bus speed in the CPU.
Turn off the monitor after a period of inactivity.
Put the computer to sleep or turn it off automatically.

Question 2

What voltage sources can most laptop power adapters use?

Answer 2

110 and 220 volts

Question 3

What can happen if you don’t use the correct adapter?

Answer 3

Receive insufficient power to turn on.
Receive insufficient power to charge the battery.
Receive an excess of power that may cause damage to the system.

Question 4

What is ACPI?

Answer 4

Advanced Configuration Power Interface

Question 5

How does ACPI control the distribution of power?

Answer 5

Alters amount of power sent to the CPU to control processing.
Dims or turns off display.
Powers down internal storage devices.

Question 6

What are the 5 ACPI power states?

Answer 6

Working
Standby
Sleep
Hibernation
Off

Question 7

Define the “working” power state

Answer 7

System is fully powered and operational

Question 8

Define the “standby” power state

Answer 8

System is in a low power state and can change quickly to the working state. RAM is fully powered; screen and storage devices are power down.

Question 9

Define the “sleep” power state

Answer 9

Sleep is similar to standby. In many systems, sleep and standby are the same. On a Mac, the system goes into hibernate mode if the power level gets below a given threshold.

Question 10

Define the “hibernate” power state

Answer 10

During hibernation, the contents of RAM are stored on internal storage to preserve system state; then, the system is completely powered down. When the system restarts, the contents of hibernation file are copied to RAM.

Question 11

Define the “off” power state

Answer 11

If you can’t define “off” then you should probably leave IT completely

Question 12

What are the key points of Windows Fast Start Up?

Answer 12

1. When a user logs off, all open programs are hibernated.
2. When the system is powered on, all open programs are restored to the system’s state where the user left off.
3. This is often called an hybrid shutdown.
4. Windows Fast Startup is enabled by default.

Question 13

What are the key points of USB Selective Suspend?

Answer 13

1. If the system detects the USB device is not in use, it will stop providing power to the port.
2. When that device become active again, the system provides power to the port enabling the device.
3. There may be a short delay accessing the USB device; however, the delay is hardly noticeable.

Question 14

List the characteristics of Nickel cadmium batteries

Answer 14

1. Develop a memory and begin to store less power as it is repeatedly recharged. To avoid battery memory problems, completely drain the battery before recharging it.
2. Take up more physical space than newer technology batteries.
3. Are very heat sensitive.
4. Are no longer used on new laptops.

Question 15

List the characteristics of Nickel metal hydride batteries

Answer 15

1. Do not develop a memory.
2. Have a 40% longer lifetime than nickel cadmium batteries.
3. Have a greater charge capacity than nickel cadmium.
4. Are less toxic than nickel cadmium.
5. Are slightly more expensive than nickel cadmium batteries.

Question 16

List the characteristics of Lithium ion batteries

Answer 16

1. Do not develop a memory.
2. Are a rechargeable battery with twice the capacity of a nickel cadmium battery and have significantly increased stability and safety.
3. Take up less physical space and weigh less than nickel cadmium or nickel metal hydride batteries with comparable power output.
4. Have a shorter lifespan than nickel metal hydride.
5. Are not heat sensitive like nickel cadmium.
6. Cannot be overcharged.
7. Are more expensive than nickel cadmium or nickel metal hydride.

Question 17

What class of fire extinguisher should you use with a Li-Ion battery fire and why?

Answer 17

Class D - because Li-Ion reacts violently with water