A net charge of 47 mC passes through the cross-sectional area of a wire in 19.0 s.
(a) What is the current in the wire?
1 A
(b) How many electrons pass the cross-sectional area in 1.0 min?
2 . electrons
I got 9.3e+22 for B but its wrong
I =q/t = 47•10^-3 / 19 = 2.47•10^-3 A,
Q =I•t1 = 2.47•10^-3•60 =0.148 C
N = Q/e =0.148/1.6•10^-19 = 9.24•10^17.
I put in 0.148 in for A and its wrong? and I put 9.24e+18 for B and its wrong?
To find the current in the wire, you can use the formula:
Current (I) = Charge (Q) / Time (t)
Given:
Charge (Q) = 47 mC = 47 * 10^-3 C
Time (t) = 19.0 s
Substituting the values into the formula:
I = (47 * 10^-3 C) / (19.0 s)
I ≈ 2.47 A
So the current in the wire is approximately 2.47 A.
To find the number of electrons passing through the cross-sectional area in 1.0 min (60 seconds), we need to know the charge carried by a single electron. This is given by the elementary charge, which is approximately 1.6 * 10^-19 C.
So the number of electrons passing through the wire can be calculated by dividing the total charge (47 * 10^-3 C) by the charge carried by a single electron (1.6 * 10^-19 C):
Number of electrons = (47 * 10^-3 C) / (1.6 * 10^-19 C)
Number of electrons ≈ 2.9375 * 10^16
Therefore, the correct answer for part (b) is approximately 2.9375 * 10^16 electrons passing through the cross-sectional area in 1.0 min.
To find the current in the wire, you can use Ohm's law, which states that current (I) is equal to the amount of charge (Q) passing through a cross-sectional area divided by the time (t) it takes for the charge to pass through.
(a) The formula to calculate current is:
I = Q / t
Given:
Q = 47 mC
t = 19.0 s
To find the current, we need to convert the charge to coulombs:
1 C = 1000 mC
So, 47 mC = 0.047 C
Now, we can calculate the current:
I = 0.047 C / 19.0 s
I ≈ 0.00247 A
Therefore, the current in the wire is approximately 0.00247 A.
(b) To determine the number of electrons passing through the cross-sectional area in 1.0 minute, we need to use the relationship between the charge and the elementary charge (e) carried by a single electron.
The elementary charge is approximately 1.602 x 10^-19 C or 1 e = 1.602 x 10^-19 C.
To find the number of electrons passing through the area, we can use the equation:
Number of electrons = Charge / Elementary charge
Given:
Charge = 47 mC = 0.047 C
Number of electrons = 0.047 C / (1.602 x 10^-19 C)
Number of electrons ≈ 2.93 x 10^21 electrons
Therefore, the correct answer for (b) is approximately 2.93 x 10^21 electrons.