Answer:
Option (C)
Explanation:
Einsteinium is an element of the periodic table grouped in the Actinide series, with atomic number 99. They are dense element and highly electro-positive. <u>They are highly radioactive</u>, i.e the atoms within the element are unstable and constantly decay until they reach a stable environment. It has 99 number of electrons and protons, 153 number of neutrons.
Due to its high radioactivity, they are health hazardous and can used in making nuclear weapons but their uses are very limited and unknown.
Thus, the correct answer is option (C).
Answer:
Angle of incidence = 20°
Angle of reflection = 20°
Explanation:
Applying,
The first Law of Refraction: The incident ray, the reflected ray and the normal at the point of incidence all lies in the plane.
From the diagram,
Angle of incidence = 90-70
Angle of incidence = 20°
From the law of reflection,
Angle of incidence = Angle of reflection
Therefore,
Angle of reflection = 20°
Answer:
Radius, r = 0.00523 meters
Explanation:
It is given that,
Magnetic field, 
Current in the toroid, I = 9.6 A
Number of turns, N = 6
We need to find the radius of the toroid. The magnetic field at the center of the toroid is given by :

r = 0.00523 m
or

So, the radius of the toroid is 0.00523 meters. Hence, this is the required solution.
Ruby, a variety of the mineral corundum is in the trigonal crystal system, with hexagonal scalenohedra crystals