Alrighty i have some questions, as well as my possible answers. We have a worksheet that i hope to do correctly since the test will be here within a week or so. Anyways ill get to it(adsbygoogle = window.adsbygoogle || []).push({});

1) a resistance irreversibly converts electrical energy into

a) mechanical work

b) chemical energy

c) heat energy

d) potential energy

a and b are out, leaving heat and potential. I am going with D here because energy is LOST as heat, i think to be converted it would have to be conserved. My answer is D)

2. A current of 100 uA flows in a circuit. How many electrons go past a point each second

a) 8.1 x 10^6

b) 4.8 x 10^12

c) 6.2 x 10^14

d) 1.5 x 10^8

I think i could use I = Delta Q/ Delta T.. i have no clue with this one

3) What potential difference is required across a 6.5ohm resistor for a 370 C of charge to flow through it in 2.5 minutes

a) 22v

b) 16v

c) 55v

d) .02v

For this, since we know resistance (6.5 ohm) and Capacitance... im a little confused, but ide say 6.5 Ohm x 370 C = 2405.. change minutes to seconds, 150seconds, 2405\ 150seconds = 16v... so my answer is B) but thats guesswork.

4)What is the equivant resistance of a 22 ohm, 40 ohm, and a 32 ohm resister connected in series.

a) 85 ohms

b) 94 " "

c) 62 " "

d) 14 " "

Rtotal = R1+R2+R3..... so 22+40+32= 94 ohms, my answer is B)

5) Capacitors of 2.5 uF, 6.6 uF, and 10 uF are connected in series, what is their equivalent capacitance.

a) 6.4 uF

b) 1.5 uF

c) 19.1 uF

d) 4.5 uF

capacitors are the same in series.. Ctotal= c1+c2+c3... 2.5+6.6+10 = 19.1 uF my answer is C)

6) Capicitances of 20 uF, 1.8 uF, 5.5 uF, and 10.6 uF are connected in parallel. What is the equivanent capicitance

for these...

1/Ctotal = 1/c1+1/c2+1/c3 (then take the inverse) 1/20+1/1.8+1/5.5+1/10.6 = .88 inverse = 1.13..

7) Appliances in the us are designed to work on 110-120v, where as appliances in europe operate on 220-240v. what would happen if you plugged a european device into u.s outlets without a converter?

a) it would work just not as well as in europe. Its the power rating, not the voltage that matters

b) it would work just not as well as in europe. Its the current rating, not the voltage that matters

c) it would work but overheat and burn up

d) It would barely work since the voltage here is too low to push enough current through the device.

I would say D. If you take a US device to europe it would blow a fuse, so i think it would work just not well at all.

I have a few more, ill post in a couple minutes

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# Homework Help: *current and resistance*

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