Answer:
C) Use a battery with more voltage.
Explanation:
The equation for the magnetic field around a coil is given by,
B = μ₀NI
where,
B = Magnetic flux density
μ₀ = permeability
N = number of turns per meter
I = Current in the wire
So when using a higher voltage battery, more current passes through the battery as resistance of the wire remains the same.
Answer:
True
Explanation:
Pressure is defined as:

where
F is the magnitude of the force perpendicular to the surface
A is the surface
Therefore, pressure is inversely proportional to the area of the surface:

this means that, assuming that the forces in the two situations (which have same magnitude) are both applied perpendicular to the surface, the force exerted over the smaller area will exert a greater pressure. Hence, the statement"
<em>"A force acting over a large area will exert less pressure per square inch than the same force acting over a smaller area"</em>
is true.
The potential energy is defined as the energy is contained in the body due to the height over the surface of the earth and it is calculated from the equation

<em>where:</em>
- PE: the potential energy in Joules.
- m: the mass of the body in kg.
- g: the acceleration due to the gravity in m/

- h: the height of the body over the earth in meters.
<em>in our problem:</em>

Answer:
(a)The work done by the man is -15.03J.
(b)The force exerted on the object is 127.4N.
Explanation:
Mass of the object pulled by the man is -13kg
Object is lifted 11.8 cm vertical with his teeth it means (displacement = +11.8cm = +0.118m)
Acceleration due to gravity is 
(a) <u>Calculating the work done</u>:
Work done = mgh
Where "m" is mass of an object, "g" is acceleration due to gravity and "h" is the displacement.


The work done by the man is -15.03J.
(b) <u>Calculating the force</u>:
Probably the man and the object are close to the exterior of the earth. If the rigidity required to maintained the object of consistent velocity interior the gravitational field of the earth is 
Thus the weight of the object is balanced by the force of the man's teeth on the object. That is
F = mg

F = 127.4N
The force exerted on the object is 127.4N.