Answer: The resistance of a lead block is
Explanation:
Resistance is defined as the difficulty of flowing of electric current through a substance. It is directly proportional to the length of the wire and inversely proportional to the area of cross section of the wire.
Mathematically,
Removing the proportionality sign, we get:
Where,
= Resistivity of the wire =
R = Resistance of the wire = ? ohm
l = Length of the wire = 15 cm
A = Area of cross-section of the wire =
Putting the values in above equation, we get:
Hence, the resistance of a lead block is
Answer:
B. They are new ideas
Explanation:
Here is how a scientific idea is accepted:
First a researcher presents the idea and its proof to the scientific community in the form of a scientific paper via the submission to a journal.
This paper then is reviewed by the experts in the field. If the results seem acceptable to them then it is published in the journal.
Now, the acceptance of the paper depends on the number of citations the paper gets.
When there is a new idea which is accepted they are unknown to the scientific community. As the paper gets older the number of people who have read the paper increases and if they think it is right then the idea gains consensus.
Answer:
Movement of Galaxies away from us.
Explanation:
Big Bang theory is the most widely accepted theory which says that the universe started with a huge expansion, it was not an explosion. By that logic everything must be moving from each other even today. This was proved by observing the Redshift in the spectrum of the galaxies which means that they are moving away from us.