<h2>Answers:</h2><h2 /><h2>a) Arrow B</h2><h2>b) Arrow E</h2>
Explanation:
Refraction is a phenomenon in which a wave (the light in this case) bends or changes its direction <u>when passing through a medium with a refractive index different from the other medium.</u> Where the Refractive index is a number that describes how fast light propagates through a medium or material.
According to this, if we observe the rays A an D passing throgh the biconcave lens, we will have two mediums:
1) The air
2)The material of the biconcave lens
This two mediums have different refractive indexes, hence the rays will change the direction.
-For the incident ray A, the corresponding refractive ray is B, because is the ray that bends after passing throgh the lens
-For the incident ray D, the refracted ray is E following the same principle.
You could use a magnetic generator or you could use hydraulic power
If a Substance conducts heat easily then it is considered a good conductor, since the electrons can move freely within the substance.
Explanation:
Polaris also called North star is the brightest star in the the constellation Ursa Minor. It remains stationary whereas entire north sky move around it. It the point of north celestial pole.
A) False. This is because All of the stars move in a counterclockwise path around Polaris.
B) False. Reason stated above.
C) True, As the stars move towards the Polaris there orbital radius decreases as they move smaller circles.
D) False, As the stars move towards the Polaris there orbital radius decreases as they move smaller circles.
E) True.
F) False.
Use of fossil fuels has not lead to increased use of wood as heat source.
Answer: Option D
<u>Explanation:</u>
Fossil fuels are materials required to generate heat or thermal energy and they are obtained by the decomposed remains of plants, animals and human beings. But the fossil fuels generally present in the bottom layer of earth crust or sometimes mixed with stones or rock minerals. So we need to highly energetic drilling devices to extract the fossil fuels.
Thus, before the introduction of fossil fuels, wood is used as the igniting source for heat energy. But the entry of fossil fuels have reduced the use of wood as igniting source in cooking, burning etc.
Thus, the use of fossil fuels have increased exchange of culture and ideas as fuels are mostly imported from other nations, it lead to development of faster transportation methods and increased the availability of products including heat, plastics and medicine. But similarly, the use of fossil fuels have not increased the use of wood as heat source, instead it decreased the use of wood as heat source.