The answer to your question is A
Answer: gravity, circuits
Explanation:
.
<h3>Explanation</h3>
The Stefan-Boltzmann Law gives the energy radiation <em>per unit area</em> of a black body:

where,
the total power emitted,
the surface area of the body,
the Stefan-Boltzmann Constant, and
the temperature of the body in degrees Kelvins.
.
.
.
Keep as many significant figures in
as possible. The error will be large when
is raised to the power of four. Also, the real value will be much smaller than
since the emittance of a human body is much smaller than assumed.
Answer: 
Explanation:
This problem can be solved by the following equation:

Where:
is the change in kinetic energy
is the electric potential difference
is the electric charge
Finding
:


Finally:

when wire is coiled upon a nail then it will posses magnetic characteristics
This is due to the coiled shape it will behave like a solenoid and the magnetic field of solenoid is given as

so here when wire is coiled up on a nail then due to the magnetic field of the coil the nail will attain magnetic characteristic.
so correct answer will be
<em>Possess magnetic properties </em>