Answer:

Explanation:
Given,
Magnetic field,B = 0.5 x 10⁻⁴ T
distance,r= 15 cm = 0.15 m
Current = ?
Using Ampere's law of magnetic field




Current in the wire is equal to 
Answer:
No
Explanation:
When the two bodies at different temperatures then heat transfer takes place between two bodies. Temperature is the necessary condition for the heat transfer.
The energy can flow due to pressure difference but the heat transfer can not take place only due to pressure difference. Heat transfer needs temperature difference.
Therefore the answer will be No.
B) Tension , is the correct answer
Answer: conduction.
Explanation:
1) A skillet or pan will be in direct contact with the food.
2) Being the skillet a solid matter, it transfers heat by conduction.
3) There are three heat transfer mechanisms: convection, conduction, radiation.
i) Convection: only happens in fluids: liquids and gases.
It is a slow mechanism and is due to the motion of the particles of fluid.
This is not the case, since the skillet is solid and the eggs are in direct contact with it. If the eggs were separated from the skillet convection might happen but it would be very slow and the eggs would take so long time to be cooked.
ii) Conduction: happens by direct contact among neighboring particles, due to their vibrations. The vibrations are only transmitted to neighboring particles, which is only possibble when they are in direct contact, so it is the classical mechanism in solids. So, the heat transfer using the skillet to cook scrambles eggs is an example of conduction.
iii) Radiation: is the transfer of heat by infrared waves. It is an important mechanism when the substances are separated by vaccum or gases and the difference of temperature is high. Yet, this is not the importante mechanism here. You feel heat radiation when you put your hand close to the skillet.
The strength of the gravitational field is given by:

where
G is the gravitational constant
M is the Earth's mass
r is the distance measured from the centre of the planet.
In our problem, we are located at 300 km above the surface. Since the Earth radius is R=6370 km, the distance from the Earth's center is:

And now we can use the previous equation to calculate the field strength at that altitude:

And we can see this value is a bit less than the gravitational strength at the surface, which is

.