Answer:
C. while the magnet is moving
Explanation:
Electromagnetic induction implies the production of electric current by mere movement of a magnet with respect to a coil or wire.
In the given question, current would be induced in the wire only when the magnet moves. That is either when the magnet is pushed into a wire, or when pulled out. But no current would flow through the wire when the magnet is left there for a while.
The current is induced because of the motion involved. Thus, the appropriate option is C.
Answer: Object B
The velocity of object A is depicted in the graph as a straight line (constant speed therefore no acceleration).
The graph indicates that the velocity of object B increases (the object is accelerating).
Answer:
Correct option : (c) period.
Explanation:
The time that is required for a vibrating object to complete one full cycle is called the time period. If f is the frequency of a wave, then the relation between the frequency and the time period is given by :

These are the characteristics of a wave. Some other characteristics are wavelength, amplitude, intensity etc. So, the correct option is (c) "period".
Answer:
18.99u or 19u
Explanation:
Mass number=No of protons+No of neutrons


- Fluorine has atomic number=9
- The Electronic configuration is given by

Answer:
Explained.
Explanation:
Only the first question has been answered
In a period from left to right the nuclear charge increases and hence nucleus size is compressed. Thus, atomic radius decreases.
In transition elements, electrons in ns^2 orbital remain same which is the outer most orbital having 2 electrons and the electrons are added to (n-1) d orbital. So, outer orbital electron experience almost same nuclear attraction and thus size remains constant.