Answer:
Explanation:
When an electric charge is immersed in an electric field, it experiences a force given by the equation
where
q is the charge
E is the magnitude of the electric field
In this problem, we have:
is the charge on the small piece of lint
is the force experienced by the charge
Therefore, we can find the magnitude of the electric field by re-arranging the equation and solving for E:
Answer:
a. R2b = R/4
Explanation:
The total resistance of a metallic wire is given by the following formula:
R = ρL/A
where,
R = Resistance of Wire
ρ = Resistivity of the material of wire
L = Length of Wire
A = Area of Wire = πr²
Therefore,
R = ρL/πr²
for the 1st wire,
radius = r = b
Therefore,
R = ρL/πb² ----------- equation 1
Now, for the second wire,
r = 2b
Therefore,
R2b = ρL/π(2b)²
R2b = ρL/πb²4
using equation 1:
R2b = R/4
therefore, correct option is:
<u>a. R2b = R/4</u>
Answer:
b) 900 W
Explanation:
The breaker trips when the current is equal to 20 A. The power (P) is the ddp (V) multiplied by the current. So, for the electric heater, the current is:
P = V*i
1500 = 120*i
i = 12.5 A
So, to become in 20 A, it's needed 7.5 A, which must come from the hairdryer. Its power must be:
P = 120*7.5
P = 900 W
A,c, and d are your answers :)
Answer:
I have made a mistake in my answer
