Answer:
to find the length just divide 7.50 and . 298
(d) option is right answer
Answer:
The best easy to make magnrets is by heating it
Answer:
9.81 × 10⁻¹⁰ C
Explanation:
Given:
Distance between the tissue and the tip of the scale, r = 6 cm = 0.06 m
Charge on the ruler, Q = - 12 μC = - 12 × 10⁻⁶ C
Mass of the tissue = 3 g = 0.003 Kg
Now,
The force required to pick the tissue, F = mg
where, g is the acceleration due to gravity
also,
The force between (F) the charges is given as:

where,
q is the charge on the tissue
k is the Coulomb's constant = 9 × 10⁹ Nm²/C²
thus,

on substituting the respective values, we get

or
q = 9.81 × 10⁻¹⁰ C
Minimum charge required to pick the tissue paper is 9.81 × 10⁻¹⁰ C
Like a lot of other things, (gravity, sound, electrostatic force), brightness also decreases as the square of the distance.
When the source moves to a new position that's 4 times as far away, its apparent brightness becomes (1/4^2) its original value.
That's 1/16 .