× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
r
4
L
4
3
d
3
M
3
l
3
V
3
s
3
d
3
a
3
g
3
j
3
Home Q & A Board Science-Related Homework Help Physics Astronomy
New Topic  
vietquocnguyen vietquocnguyen
wrote...
Go to Answer
Posts: 498
Rep: 0 0
6 years ago
A device that doesn't obey Ohm's law is a
 
  A) copper wire.
  B) silver bar.
  C) light bulb.
  D) resistor.
  E) tungsten wire.

Question 2

If the efficiency of a reversible engine is 28.,
 
  (a) what is its COP operated as a refrigerator?
  (b) what is its COP operated as a heat pump?

Question 3

The capacitive reactance is directly proportional to the frequency of the applied ac signal.
 
  Indicate whether the statement is true or false

Question 4

A rock sample contains 1/2 microgram of the parent radioactive isotope U-235 and 1/2 microgram of its daughter isotope Pb-207. If the half-life of this decay is 700 million years, how old is this rock?
 
  A) 1400 million years
  B) 2100 million years
  C) 700 million years
  D) 350 million years
Read 53 times
2 Replies
Replies
Answer verified by a subject expert
MtnimpMtnimp
wrote...
#1
Posts: 365
Rep: 0 0
6 years ago
Sign in or Sign up in seconds to unlock everything for free
1

Related Topics

wrote...
#2
6 years ago
This is very helpful, my teacher this year is not good
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1632 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 1190
  
 258
  
 1139
Your Opinion
Previous poll results: What's your favorite math subject?