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.
Answer:
Zero
Explanation:
It is given that,
A person swims to the other end of a 20m long pool and back.
We need to find his displacement.
Displacement = shortest path covered
He reaches at the same position as from where he has started. It means the shortest path covered is equal to 0 i.e. his displacement is zero.
Using the precise speed of light in a vacuum (

), and your given distance of

, we can convert and cancel units to find the answer. The distance in m, using

, is

. Next, for the speed of light, we convert from s to min, using

, so we divide the speed of light by 60. Finally, dividing the distance between the Sun and Venus by the speed of light in km per min, we find that it is
6.405 min.
Melting, of course. Just as how an ice cube melts to water.
I think the corect answer would be C. When a police officer receives information that you are speeding in your vehicle, she is using the frequency of the wave to measure the Doppler Effect. As the speed of a vehicle increases, the greater the change of the frequency of the waves would be transmitted to the radar guns which is being used by the police officer. Doppler effect is an effect that is observed in sound and light waves as these waves move away or to the direction of the observer. This is being used in many applications like in astronomy, weather balloons, the radar guns,and for underwater researches.