Answer:
Principal focus of a concave mirror. The principal focus of a concave mirror is a point on its principal axis to which all the light rays are parallel and close to the axis converge after reflection from the concave mirror.
Focal length of a concave mirror. The focal length of a concave mirror is the distance between its pole and the principal focus
The reflecting surface of a spherical mirror forms a part of a sphere. The centre of this sphere. This point is called the centre of curvature of the spherical mirror. Center of curvature can also be defined as the point in the centre of the sphere from which the mirror was sliced. It is represented by the letter C. Please note that the centre of curvature lies outside the mirror's reflecting surface. The centre of curvature of a concave mirror lies in front of it. However, it lies behind the mirror in case of a convex mirror.
If a concave mirror were thought of as being a slice of a sphere, then there would be a line passing through the center of the sphere and attaching to the mirror in the exact center of the mirror. This line is known as the principal axis.
Answer : D) Circuit A
This circuit is the only circuit where it is not complete, having and open spot towards the bottom of it, making it and open circuit.
A) f = 1.8 rev/s = 2 Hz
<span>T = 1 / f = 0.55s
B) not really sure..srry
C) </span><span>T = 2 pi √ ( L / g ) </span>
<span>0.57 = 2 x 3.14 x √ ( 0.2 / g )
</span><span>
g = 25.5 m/s²
</span>
Hope this helps a little at least.. :)
note-Unlike the planetary model, our model view is that the electrons move around the nucleus in an electron cloud. Modern atomic theory states that the atom is a diffuse cloud surrounding a small, dense nucleus. Identify which particle is in the nucleus. note-Neutron is a particle in the nucleus.
