Assignment 1_Electronics Engineering | Assignments Electronics engineering

ALARDE, ANGELA LORRAINE C. OCTOBER 10, 2020

BS ECE- ECE21S1 PROF. ERIC YBANEZ

Assignment

1. Suppose that your car will not start. To determine whether the battery is faulty, you turn

on the light switch and find the lights are dim, indicating a weak battery. You borrow a

friend’s car and a set of jumper cables. However, how do you connect his car’s battery to

yours? What do you want his battery to do?

- To connect his car’s battery to mine we will use jumper cables the red clamp will

be attached to the positive side of each battery and the other clamp or the black

clamp to the negative side of the battery, then the car with the live battery will start

the car to transfer some of the charge to the other battery. We need the dead

battery to start up using some of the charge of a live battery to be able to start up

the car engine for the car to move to a nearest shop to fix the battery.

2. A Universal Serial Bus (USB) port is a common feature on both desktop and notebook

computers as well as many handheld devices such as MP3 players, digital cameras, and

cell phones. The USB 2.0 specification permits data transfer between a computer and a

peripheral device at rates up to 480 megabits per second. One important feature of USB

is the ability to swap peripherals without having to power down a computer. USB ports

are also capable of supplying power to external peripherals. A USB cable is a four

conductor cable with two signal conductors and two conductors for providing power. The

amount of current that can be provided over a USB port is defined in the USB

specification in terms of unit loads, where one-unit load is specified to be 100 mA. All

USB ports default to low-power ports at one-unit load, but can be changed under

soft-ware control to high-power ports capable of supplying up to five unit loads or 500

mA.

a. A 680 mAh lithium-ion battery is standard in a Motorola RZZR®. If this battery is

completely discharged (i.e., 0 mAh), how long will it take to recharge the battery to its full

capacity of 680 mAh from a low-power USB port? How much charge is stored in the

battery at the end of the charging process?

Given:

- 680 mAh

- 100 mA

Required: Time for the battery to charge to its full capacity, and how much charge is stored in

the battery at the end of the charging process?

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ALARDE, ANGELA LORRAINE C. OCTOBER 10, 2020

BS ECE- ECE21S1 PROF. ERIC YBANEZ

Assignment

Suppose that your car will not start. To determine whether the battery is faulty, you turn on the light switch and find the lights are dim, indicating a weak battery. You borrow a friend’s car and a set of jumper cables. However, how do you connect his car’s battery to yours? What do you want his battery to do? - To connect his car’s battery to mine we will use jumper cables the red clamp will be attached to the positive side of each battery and the other clamp or the black clamp to the negative side of the battery, then the car with the live battery will start the car to transfer some of the charge to the other battery. We need the dead battery to start up using some of the charge of a live battery to be able to start up the car engine for the car to move to a nearest shop to fix the battery.
A Universal Serial Bus (USB) port is a common feature on both desktop and notebook computers as well as many handheld devices such as MP3 players, digital cameras, and cell phones. The USB 2.0 specification permits data transfer between a computer and a peripheral device at rates up to 480 megabits per second. One important feature of USB is the ability to swap peripherals without having to power down a computer. USB ports are also capable of supplying power to external peripherals. A USB cable is a four conductor cable with two signal conductors and two conductors for providing power. The amount of current that can be provided over a USB port is defined in the USB specification in terms of unit loads, where one-unit load is specified to be 100 mA. All USB ports default to low-power ports at one-unit load, but can be changed under soft-ware control to high-power ports capable of supplying up to five unit loads or 500 mA. a. A 680 mAh lithium-ion battery is standard in a Motorola RZZR®. If this battery is completely discharged (i.e., 0 mAh), how long will it take to recharge the battery to its full capacity of 680 mAh from a low-power USB port? How much charge is stored in the battery at the end of the charging process? Given:

680 mAh
100 mA Required: Time for the battery to charge to its full capacity, and how much charge is stored in the battery at the end of the charging process?

Known: Q = It Solution:

t = Q/I, 680 mAh/100mA = 6.8 hours
Q = It, 680 mAh(60s/h) = 40,800 mAs(1As/1000mAs) = 40.8 As = 40.8 C Answer:
Time to charge to full capacity is 6.8 hours
The charge stored in the battery at the end of the charging process is 40.8 C b. A third-generation iPod® with a 630 mAh lithium-ion battery is to be recharged from a high-power USB port supplying 150 mA of current. At the beginning of the recharge, 7. C of charge is stored in the battery. The recharging process halts when the stored charge reaches 35.9 C. How long does it take to recharge the battery? Given:
630 mAh lithium-ion Battery
150 mA current
7.8 charge are stored in the battery before charging
35.9 C maximum charge of the battery Required: How long does it take to recharge the battery? Known: t = Q/I Solution: 35.9 C – 7.8 C = 28.1 C = 28.1 As = 28,100 mAs(1hr/60s) = 468.3 mAh t = 468. mAh/ 150 mA = 3.12 hours Answer: -it takes 3.12 hours for the battery to recharge

TV Picture Tube One important application of the motion of electrons is found in both the transmission and reception of TV signals. At the transmission end, a TV camera reduces a scene from an optical image to an electrical signal. Scanning is accomplished with a thin beam of electrons in an iconoscope camera tube. At the receiving end, the image is reconstructed by using a cathode-ray tube (CRT) located in the TV receiver.3 The CRT is depicted in Fig. 1.17. Unlike the iconoscope tube, which produces an electron beam of constant intensity, the CRT beam varies in intensity according to the incoming signal. The electron gun, maintained at a high potential, fires the electron beam. The beam passes through two sets of plates for

Given:

5 mA current
Resistor marked with brown, black, red, gold
6.5 V voltage drop Required: If the voltage drop is within the resistor’s tolerance rating Known: V = IR Solution: R = V/I, R = 6.5V/.005A = 1300 ohms The 4-band resistor: Brown – 1 Black – 0 Red – x 100 ohms Gold – 5% = 1000 ohms with 5% tolerance Answer: The resistor is not within its Tolerance

A homeowner uses 100-watt incandescent lamps as a heater in an outside well pump house to protect the pump from freezing in cold weather. Unfortunately, however, the lamp can burn out and leave the pump unprotected. You have been asked to install a hearth that will not burn out and leave the pump unprotected. You have available a 100- watt, 150-ohm wire-wound resistor. Can this resistor be connected to the 120-volt source without damage to the resistor? If so, what would be the power output of the resistor? (Hint: Use power formula) Given:

100 watts
150-ohm wire-wound resistor
120-volt source Required: power output of the resistor Known: P = V^2/R Solution: P = (120V) ^2/150 ohm = 96 watts V = ((100watts) (150ohms))^1/2 = 122 volts Answer: yes, a 150-ohm wire-wound resistor can be connected to a 120-volt source. And the

power output will be 96 watts.

Assignment 1_Electronics Engineering, Assignments of Electronics engineering

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Download Assignment 1_Electronics Engineering and more Assignments Electronics engineering in PDF only on Docsity!

ALARDE, ANGELA LORRAINE C. OCTOBER 10, 2020

BS ECE- ECE21S1 PROF. ERIC YBANEZ