Electric Energy | Show Me The Physics

Electric Energy lesson illustration

Is this circuit a Series or Parallel? Why?

Electric Energy lesson illustration

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Series or Parallel?

Electric Energy lesson illustration

Answer - Parallel - same V

Electric Energy lesson illustration Electric Energy and Heat

(W) Electric energy consumed or released as heat

(All equations on reference table)

(J) W = Pt = [V²/R]t

= VIt = I²Rt

An electric iron operating at 120 volts draws 10. amperes of current. How much heat energy is delivered by the iron in 30. seconds?

a) 1.2 x 10³ J	c) 3.6 x 10⁴ J
b) 3.0 x 10² J	d) 3.6 x 10³ J

V = 120 V

I = 10. A

t = 30. sec

W = ?

W = VIt

= 120. V(10. A)(30. sec)

W = 3.6 x 10⁴ J

Electric Energy lesson illustration

What's wrong with this picture?

Electric Energy lesson illustration

Ammeter should be
in series with resistor

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Circuits - Series and Parallel

Electricity Unit Review

Check Your Understanding

5 quick questions — pick an answer to see if you’re right.

1. Which unit is used for electric energy in the equation W = VIt?

2. An electric iron at 120 V draws 10. A. How much heat energy does it deliver in 30. s?

3. A 100. W light bulb is on for 60. s. How much electrical energy does it use?

4. A current of 2.0 A flows through a 10. Ω heater for 5.0 s. How much energy is released as heat?

5. A toaster runs at the same power for twice as long. The electric energy it uses: