The bulbs are now connected in series
Questions 2, 4, 5, 6, 8, 9, 28 Problems 1, 2, 14, 15, 19, 20, 28, 41, 42, 45, 50 Q2 Under what condition does the potential difference across the terminals of a battery equal its emf? Can the terminal voltage ever exceed the emf? When there is no load, the terminal voltage is the same as the emf. The terminal voltage can never exceed the emf. Q4 Two sets of Christmas-tree lights are available. For set A, when one bulb is removed (or burns out the remaining bulbs remain illuminated. For set B, when one bulb is removed, the remaining bulbs do not operate. Explain the differnce in wiring of the two sets. Set A is connected in parallel. Set B is connected in series. Q5 How would you connect resistors so that the equivalent resistance is larger than the individual resistance? Resistors in series will provide an equivalent resistance that is larger than the largest individual resistance. Q6 How would you connect resistors so that the equivalent resistance is smaller than the individual resistance? Resistors in paralled will provide an equivalent resistance that is smaller than the smallest individual resistance. Q8 When resistors are connected in series, which of the following would be the same for each resistor: potential difference, current, power? Resistors in series share a common current. Q9 When resistors are connected in parallel, which of the following would be the same for each resistor: potential difference, current, power? Resistors in parallel share a common voltage or potential difference. Q28 A series circuit consists of three identical lamps connected to a battery as in Figure 28.29. When the switch S is closed, what happens (a) to the intensities of lamps A and B; (b) to the intensity of lamp C; (c) to the current in the circuit; and (d) to the voltage drop across the three lamps? (e) Does the power dissipated in the circuit increase, decrease or.
Electrical systems and control In this chapter, you will learn how to make light bulbs light up by building electric circuits. You'll learn about circuit components, input and output devices, and control devices such as switches. Finally, you will learn how to draw these components in circuit diagrams, using the correct symbols. Figure 1 Explore simple circuits Make bulbs light up You need all the components (parts) shown in Figure 2 to do this activity. Figure 2: Components to make an electric circuit Divide into teams of four to six learners. Two teams can work together if there is only one cell per team. Discuss the following in your teams, and do the experiments: Find out how to connect the parts to make the bulb light up. Find three or more ways to make the bulb light up. Touch the glowing bulb using your fingers. What does it feel like? Look inside the glass part of the bulb. Which part of the bulb gets hot? What happens when you connect two cells instead of one cell? How can you make the bulb flash on and off? From this activity you found that a bulb will glow only if the wires touch it on the screw contact and the solder knob at the bottom. You found that you must connect metal parts to make a path from the knob of a cell, through the bulb, and back to the flat end of a cell. This path is called a circuit. The current will not flow if there is a gap in the path of the conductors. An electric circuit is a complete path of conductors. The cells cause a current of electricity to flow around the circuit. The current will flow only if the circuit has no breaks in it. The cells provide the energy to make the electricity flow through the circuit, and the electricity flowing through the filament wire inside the light bulb makes it glow. Cells use a chemical reaction to make electricity flow through a circuit. In Chapter 9, you will learn more about the chemical.
I crafted this answer for this question in the first place but since it got closed, I will post it here to at least contribute. 1) The brightness of a light bulb depends on various parameters, most of them being intrinsic properties of light bulbs. Essentially, the brightness depends upon the luminous flux of the light source. However, light sources which emit light with different wavelengths but same luminous flux can be perceived to have different brightness levels. Therefore, luminous flux is useful if we are comparing the brightness of light sources which emit light with same wavelength. For incandescent light bulbs, brightness or luminous flux is directly related to the heat energy due to the flowing current in a conductor since these type of light bulbs are used by heating the filament until it emits visible light(assuming we have an incandescent light bulb here because other light sources like LED will have different properties). What is the term used to specify the heat energy generated by the flowing current per unit time? Power. Therefore, we should increase the power due to a current source as much as possible to increase the brightness of the light bulb. To find which parameters we should play with to increase the power, we can use Joule- Lenz law which states that: $ Q\propto I^2 Rt $ Therefore, since power is $\frac Wt$, we can derive the expression that is proportional to the power: $ P\propto I^2 R $ However, this expression can deceive you to think that increasing the resistance of the light bulb increases the brightness. Since altering the resistance will also decrease the current passing through the light bulb and even exponentially decrease the power, we can derive a more reliable formula by using the specialized form of Ohm's law($ V= IR$). Assuming we have an ideal conductor here, one can find that; $ P\propto VI $ Overall, you need to increase.