1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Genrish500 [490]
3 years ago
7

A focal arrangement that has a secondary mirror that reflects the focused light back through a hole in the primary mirror is a _

______________.
a. Cassegrain focus
b. Newtonian focus
c. Schmidt-Cassegrain focus
d. Schmidt focus
Biology
1 answer:
sveticcg [70]3 years ago
7 0
<span> a. Cassegrain focus</span> is the focal arrangement in a Cassegrain reflector used in optical telescopes and radio antennas. The primary mirror is a concave mirror, and the secondary mirror that reflects the focused light back to it is a convex mirror.
You might be interested in
Describe how a Newton's cradle illustrates the conservation of energy.
yulyashka [42]
D is the correct answer
3 0
3 years ago
Read 2 more answers
What species is/are formed at the anode of the alkaline fuel cell?
umka21 [38]

Fuel cells can make an electricity from a simple electrochemical reaction in which oxygen and hydrogen combine to form water. There are several different types of fuel cell but they are all based around a central design which consists of two electrodes, a negative anode and a positive cathode. These are separated by a solid or liquid electrolyte that carries electrically charged particles between the two electrodes. A catalyst, such as platinum, is often used to speed up the reactions at the electrodes. Fuel cells are classified according to the nature of the electrolyte. Every type needs particular materials and fuels and is suitable for any applications. The article below uses the proton exchange membrane fuel cell to illustrate the science and technology behind the fuel cell concept but the characteristics and applications of the other main designs are also discussed.  Proton Exchange Membrane Fuel Cells (PEMFC)

The hydrogen ions permeate across the electrolyte to the cathode, while the electrons flow through an external circuit and provide power. Oxygen, in the form of air, is supplied to the cathode and this combines with the electrons and the hydrogen ions to produce water. These reactions at the electrodes are as follows:

Anode: 2H24H+ + 4e-

Cathode: O2 + 4H+ + 4e- 2H2O

Overall: 2H2 + O22H2O + energy

PEM cells operate at a temperature of around 80°C. At this low temperature the electrochemical reactions would normally occur very slowly so they are catalysed by a thin layer of platinum on each electrode.

3 0
3 years ago
WILL GIVE BRAINLEST
Andrej [43]

the answer is

chromoplast


3 0
3 years ago
Function of epiglottis​
Butoxors [25]

Answer:

prevents secretion of upper air passage

Explanation:

to prevent foods and drinks from falling down the airway which is called aspiration and may lead to pneumonia

7 0
2 years ago
What is pseudoscience? Students have been comparing pseudoscience with "real" science. Their teacher told them to make a chart c
KIM [24]

Answer:

b and e

Explanation:

i got it correct in usatestprep  :)

5 0
2 years ago
Other questions:
  • Am i correct and if i'm not can you help
    10·2 answers
  • What kind of questions would you ask, if you are provided with the following materials: Sugar, stir stick, access to warm or col
    6·1 answer
  • White vinegar is an alternative cleaning product that helps:
    6·2 answers
  • What process in cells undergoing meiosis increases genetic diversity
    9·1 answer
  • What would happen if a large organism was made of a single cell?
    6·1 answer
  • Southern Italy is very close to the border of two tectonic plates. Which of these facts is most directly related to the closenes
    9·2 answers
  • Assume that producers in an ecosystem have 1,000,000 kilocalories of energy. How much energy is available to primary
    7·1 answer
  • 23. Each trait has two alleles. How many alleles would have to be a dominant allele for the offspring to express a dominant trai
    13·1 answer
  • 5
    11·1 answer
  • What controls traits and inheritance?<br> gametes<br> nucleic acids<br> proteins<br> temperature
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!