Answer:
D. Validity group
Explanation:
A validity group is not necessarily a component of a normal experiment.
A normal experiment is made up of the dependent variables, independent variables, and most times the control group.
- The dependent variable is one that relies on the outcome of the effect produced from the experimental design
- The independent variable is the one that causes a desired effect under the study.
- The control group is a group that does not receive any treatment nor attenuation of the conditions.
The length of a wave so, therefore its D.
Question :
If a body acquires a charge of -0.02 C, has it gained or lost electrons? Many?
Solution :
We know, charge gained is shown by negative sign.
Since, charged acquired is given as -0.02 C .
Therefore, it is body has gained electrons.
Now, number of electrons is given by :

Hence, this is the required solution.
Answer:
In constructive waves, a <u><em>greater</em></u> amplitude wave is formed. In destructive waves, a wave with a <u><em>smaller</em></u> amplitude is formed. (option A)
Explanation:
Interference is called the superposition or sum of two or more waves. Depending mainly on the wavelengths, amplitudes and the relative distance between them, there are two types of interference: constructive or destructive.
Constructive interference occurs when there are two waves of identical or similar frequency (both have motions equal to an even number of similar wavelengths) and overlap the peak of one with the peak of the other. These effects add together and make a wave of greater amplitude. All of this is possible because the waves were in the same phase in the beginning (in the same position).
Destructive interference occurs in the opposite case to constructive. When the crest of one wave overlaps the valley of the other, they cancel out since they are in different phases when they overlap (they were in different positions). That is, as in the case of constructive waves they were added, in the case of destructive waves they cancel out (subtract).
So, <u><em>In constructive waves, a greater amplitude wave is formed. In destructive waves, a wave with a smaller amplitude is formed. </em></u>
Answer:
1.37 ×10^-3 T
Explanation:
From;
B= μnI
μ = 4π x 10-7 N/A2
n= number of turns /length of wire = 1700/0.75 = 2266.67
I= 0.48 A
Hence;
B= 4π x 10^-7 × 2266.67 ×0.48
B= 1.37 ×10^-3 T