Question 15

A 40.0-mH inductor is connected to a North American electrical outlet (ΔVrms = 120 V, f = 60.0 Hz). Assuming the energy stored i

trasher [3.6K]

Explanation:

It is given that,

Inductance, $L=40\ mH=40\times 10^{-3}\ H$

RMS value of voltage, $v_{rms}=120\ V$

Frequency, f = 60 Hz

We need to find the energy stored at t = (1 /185) s. It is assumed that energy stored in the inductor is zero at t = 0. So,

The current flowing through the inductor is given by :

$I_t=\dfrac{V_o}{X_L}\ (sin\ \omega t-\dfrac{\pi}{2})$

$I_t=\dfrac{\sqrt{2} V_{rms}}{X_L}\ (sin\ \omega t-\dfrac{\pi}{2})$

$I_t=\dfrac{120\sqrt{2}}{2\pi f L}\ sin(2\pi f t-\dfrac{\pi}{2})$

$I_t=\dfrac{120\sqrt{2}}{2\pi\times 60\times 40\times 10^{-3}}\ sin(2\pi \times 60\times \dfrac{1}{185})-\dfrac{\pi}{2})$

$I_t=\dfrac{120\sqrt2}{15.07}\ sin(2\pi \times 60\times \dfrac{1}{185}-\dfrac{\pi}{2})$

I = 0.091 A

Energy stored in the inductor is, $U=\dfrac{1}{2}LI^2$

$U=\dfrac{1}{2}\times 40\times 10^{-3}\times (0.091)^2$

U = 0.000165 Joules

Hence, this is the required solution.

6 0

3 years ago

A marble is dropped from rest and falls for 2.3 seconds. Find its final velocity.

juin [17]

Answer:

23 m/s downward

__________________________________________________________

Taking the downward direction as positive

We are given:

Initial velocity of the marble (u) = 0 m/s

Time interval (t) = 2.3 seconds

Final velocity (v) = x m/s

Solving for the Final velocity:

Acceleration of the Marble:

We know that gravity will make the marble accelerate at a constant acceleration of 10 m/s

Final velocity:

v = u + at [First equation of motion]

x = 0 + (10)(2.3) [replacing the given values]

x = 23 m/s

Hence, after 2.3 seconds, the marble will move at a velocity of 23 m/s in the downward direction

4 0

2 years ago

When a person speaks, a sound intensity is generated that is 600 times greater than when the person whispers. What is the differ

Charra [1.4K]

Answer:

Originally : Level = log I / I0

Currently: Level = 10 log I / I0

Level = 10 log 600 = 10 * 2.78 = 27.8

Note the term 1 bel = 10 decibels

5 0

2 years ago

Answers are - A 235 N B 376 N C 271 N D 188 N E 470 N

amm1812

Answer:

C

Explanation:

8 0

3 years ago

Which things determine an element's electronegativity? Check all that apply. A. The size of the atom of that element B. Whether

KengaRu [80]

D. The number of electrons

6 0

2 years ago