Answer:
B. Magnetic field
Explanation:
When metal filings are close to a magnetic field, they tend to align with it.
In other words, the show the direction of the magnetic field at each point.
even by guessing, there is no electric field around steady magnets, nor the gravitational attraction has nothing to dp with that. :)
Answer : The correct option is, (D) 278 K
Explanation :
We are given temperature .
Now the conversion factor used for the temperature is,
where, K is kelvin and is Celsius.
Now put the value of temperature, we get
Therefore, the temperature 278 K is equal to the
Answer:
They have a dual wave-particle nature.
Explanation:
Electromagnetic waves consist of periodic oscillations of electric and magnetic field in a plane perpendicular to the direction of motion of the wave (in fact, they are also classified as transverse waves).
Electromagnetic waves have a wave nature, however they also have particle nature - in fact, it has been proved in some experiment (e.g. photoelectric effect) that in some conditions they act as packets of particles - called photons. Therefore, the option
They have a dual wave-particle nature.
is correct.
Other options are wrong because:
They are all invisible. --> False because visible light (which is part of the electromagnetic spectrum, so they are electromagnetic waves) is visible
They can only travel without a medium. --> False because they can also travel in a vacuum
They are slower than sound waves. --> False because they travel much faster (they travel at the speed of light in a vacuum, , while sound travels at 343 m/s in air, for instance)