Answer:
If iron, nickle, or cobalt is an answer choice, those are the three metals that are purely magnetic.
Answer:
1. The current will drop to half of its original value.
Explanation:
The problem can be solved by using Ohm's law:

where
V is the voltage across the circuit
R is the resistance of the circuit
I is the current
We can rewrite it as

In this problem, we have:
- the resistance of the circuit remains the same: R' = R
- the voltage is decreased to half of its original value: 
So, the new current will be

so, the current will drop to half of its original value.
Answer:
F=ma
here F is force, m is mass and a is accelaration,
According to the question,
F=3*F= 3F
m= 1/3 of m= m/3
a= ?
so the equation becomes,
3F= m/3*a
3F*3= ma
9F=ma
F= ma/9
Therefore accelaration reduces by 1/9.
I am not very sure.
Convex.
Concave curved inward (like how a cave foes in) and convex curves outward. Reflected and refracted do not apply to a lens.
The harmonic frequency of a musical instrument is the minimum frequency at which a string that is fixed at both ends in the instrument may vibrate. The harmonic frequency is known as the first harmonic. Each subsequent harmonic has a frequency equal to:
n*f, where n is the number of the harmonic and f is the harmonic frequency. Therefore, the harmonic frequency may be calculated using:
f = 100 / 2
f = 50 Hz