The water has an irregular surface so if the light rays fall on top then it will reflect oppositely or in some cases may refract, so the fish will seem a bit smaller or further or closer in anyway, example if u put a straw in water it looks bent but is it ? nope. So the main reason is that it refracts which makes the accuracy lesser which make it difficult.
Answer: option 4: A wire that is 2-mm thick and coiled.
Explanation:
The current in each wire is same. The magnetic field due to a current carrying wire increases if the wire is coiled with the more number of turns. A thick wire would cause low resistance to the current. Hence, a 2-mm thick wire which is coiled would produce the strongest magnetic field.
It is the study of cognitive functions.
Answer:
a) always. b) electric field lines are defined by the path positive test charges travel.
Explanation:
By convention, field lines always follow the direction that it would take a positive test charge (small enough so it can´t disrupt the field created by a charge distribution), under the influence of an electric field, at the same point where the test charge is located.
So any positive charge, subject to an electric field influence, moves along the field line that passes through its current position, in the same way that a positive test charge would.
We could say also that the electric force on a positively charged particle is in the same direction as the electric field that produces that force (due to some charge distribution) , which is true, but it doesn´t explain why.
