QUESTION Four people tell you they have a negative charge of a certain value. Which one is
not telling the truth? Mine is 1.90x10-18 Coulomb. Mine is 1.6x10-18 Coulomb. Mine is
1.92x10-18 Coulomb. Mine is 2.4x10-16 Coulomb. QUESTION 2 Two charges Q1 and Q2 are
separated by a distance D. If both Q1 and D are doubled, the force is increased by a factor of 2
decreased by a factor of 2 increased by a factor of 4 O remains the same O decreased by a factor
of 4
Solution
1.
Answer is A)Mine is 1.9*10 -18
Coloumb
Since 1.9*10 -18
Coloumb charge is not integral multiple of 1.6*10 -19
C
2.
From Coloumb's law force of attraction or repulsion between charges is
F=KQ 1 Q 2 /D 2
If Q 1 and D are doubled then
F New =K(2Q 1 )Q 2 /(2D) 2
=(1/2)[KQ 1 Q 2 /D 2
]
Therefore
F new =(1/2)F
Answer is b) Decreased by a factor of 2