Answer:
B 5.0 A
.
Explanation:
Hello.
In this case, since we know the charge (1200 C), time (4 min =240 s) and resistance (10Ω) which is actually not needed here, we compute the current as follows:

Then, for the given data, we obtain:

Therefore, answer is B 5.0 A
.
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The resistance of the cylindrical wire is
.
Here
is the resistance,
is the length of the wire and
is the area of cross section. Since the wire is cylindrical
. Rearranging the above equation,

Here
.
Substituting numerical values,

The length of the wire is 
Answer:
All magnets have two poles: the North Pole and the South Pole.
Magnets attract ferromagnetic materials such as iron, nickel, and cobalt.
The magnetic force of a magnet is stronger at its poles than in the middle.
A freely suspended magnet always points in North-South direction.
Hope this helps
The coefficient of friction is 0.5.
<h3>What is Coefficient of friction?</h3>
The ratio of friction force to normal force is known as the coefficient of friction (COF), which has no dimensions. Those materials are said to as lubricous if their COF is less than 0.1. Surface roughness and COF are dependent on the composition of the materials.
Initial velocity, u=30m/s
time taken = 6s
Final velocity, v=0
Acceleration of friction, a=μg=10μms⁻²
Apply first kinematic equation of motion,
v - u = at
0 - 30 = (-10μms⁻²) × 6
-30 = -60μ
μ = 1/2
μ = 0..5
Hence, coefficient of friction is 0.5
to learn more about Coefficient of friction go to - brainly.com/question/14121363
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