Answer:
option(d)
Explanation:
The frequency of a wave is the property of the source of wave.
The velocity of all the electromagnetic waves is same as the speed of light. It only changes as the light passes through one medium to another.
The frequency is defined as the number of waves coming out from the source in 1 second.
As the frequency of wave increases, the number of wave coming per second increases.
So, the number of waves passing by increases but the speed remains same.
Option (d)
Answer:
θ=180°
Explanation:
The problem says that the vector product of A and B is in the +z-direction, and that the vector A is in the -x-direction. Since vector B has no x-component, and is perpendicular to the z-axis (as A and B are both perpendicular to their vector product), vector B has to be in the y-axis.
Using the right hand rule for vector product, we can test the two possible cases:
- If vector B is in the +y-axis, the product AxB should be in the -z-axis. Since it is in the +z-axis, this is not correct.
- If vector B is in the -y-axis, the product AxB should be in the +z-axis. This is the correct option.
Now, the problem says that the angle θ is measured from the +y-direction to the +z-direction. This means that the -y-direction has an angle of 180° (half turn).
Answer:
He requires 1 gram of mass.
Explanation:
The density is defined as:
(1)
Where m is the mass and V is the volume.
Then, m can be isolated from equation 1 in order to determine the mass.
(2)
Hence, he requires 1 gram of mass.
