Answer:
Explanation:
1. A solenoid is a coil which has many turns. When current flows through a solenoid, it behaves as an electromagnet. This behavior is due to the magnetic effect of an electric current thereby causing one end of the solenoid to behave as a north pole, while the other end as a south pole.The external influence of the earth's magnetism constrains the solenoid to come to rest in a N-S position just like a bar magnet.
2. The magnetic compass can be used to trace the alignments or patterns of the magnetic field around a current carrying wire. When current flows in a wire, it induces magnetic field around it. If the value of current is increased, the strength of the magnetic field would increase and vice versa. This shows that current is proportional to the strength of the magnetic field produced around the wire. Thus this causes a deflection of the compass appropriately, as the deflection of the compass is proportional to the strength of the field.
Answer:

Explanation:
Let m is the mass of both cars. The first car is moving with speed v and the other car is moving with speed 2v. The only force acting on both cars is the centripetal force.
For faster car on the road,

v = 2v

..........(1)
For the slower car on the road,
............(2)
Equation (1) becomes,


So, the frictional force required to keep the slower car on the road without skidding is one fourth of the faster car.
Answer:
From spectral lines astronomers can determine not only the element, but the temperature and density of that element in the star. The spectral line also can tell us about any magnetic field of the star. The width of the line can tell us how fast the material is moving. We can learn about winds in stars from this.
Explanation:
The energy from the sun is what sustains the solar system. But this is only a small part of the universe. So it will be inaccurate to say that the source of all energy in the universe is the sun.
<span>The universe is made up of several other galaxies including our own milky way. But looking at these components of the universe, they are made up of stars. Considering that all other stars are similar to our sun, which by the way is also a star, then we can put it that their collective energies is what constitutes the energy source for the universe. </span>
<span>But here we have only considered what we know about the universe, since man has been able to explore only a minute fraction of the universe, it wont be fair to argue that this is absolute. There may be other energy sources out there that have not yet been discovered, but for now, the idea behind the summation of celestial energies should suffice. </span>
6 units of energy were transferred into heat.