There are 6 types of quarks.
Answer: C. 6
The statement "<span>Forces always act alone" is false. Force do not always act alone. It is always accompanied by another force that is always opposite to it. </span>
Explanation:
The total resistance used to calculate the total resistance of the two parallel resistor is given by :

Taking reciprocal of the above equation.

We can also write the above equation as :

On simplification of above equation,

or

Hence, proved.
Answer:
True
Explanation:
The normal line is defined as the line which is perpendicular to the reflecting surface at the point where the incident ray meet with the reflecting surface.
The angle of incident is defined as the angle which is subtended by the incident ray with respect to the normal ray by consider the normal ray as the base line and angle is measured from the point where incident ray is incident on the reflecting surface of the mirror.
Similarly reflecting ray can be defined as the ray which is reflected after the incident of a ray and the angle subtended by the reflecting ray is measure with respect to normal ray by considering normal ray as a base line.
Therefore, the normal ray is the perpendicular line to the reflecting surface at the point of incidence.