Chapter 19, Problem 13P

(a)

To determine

The voltage across each bulb.

Answer to Problem 13P

The voltage across each bulb is $13.75\text{V}$ .

Explanation of Solution

Given info:

Voltage across bulbs, $V=110\text{V}$

Number of bulbs in series, $n=8$

Formula Used:

The expression to calculate the voltage across each bulb is,

  $V_b=\frac{V}{n}$

Calculation:

Substitute all the values in the above expression.

  $\begin{array}{c}{V}_b=\frac{110\text{V}}{8}\\ =13.75\text{V}\end{array}$

Conclusion:

Therefore, the voltage across each bulb is $13.75\text{V}$ .

(b)

To determine

The resistance of each bulb and the power dissipated across each bulb.

Answer to Problem 13P

The resistance of each bulb is $27.5\Omega$ and the power dissipated across each bulb is $6.875\text{W}$ .

Explanation of Solution

Given info:

The current through each bulb is, $I=0.5\text{A}$ .

Formula Used:

The expression to calculate the resistance of each bulb is,

  $R=\frac{V}{nI}$

The expression to calculate the power dissipated across each bulb is,

  $P=I^{2}R$

Calculation:

Substitute all the values in the above expression.

  $\begin{array}{c}R=\frac{110\text{V}}{8\left(0.5\text{A}\right)}\\ =27.5\Omega \end{array}$

Substitute all the values in the above expression.

  $\begin{array}{c}P={\left(0.5\text{A}\right)}^2\left(27.5\Omega \right)\\ =6.875\text{W}\end{array}$

Conclusion:

Therefore, the resistance of each bulb is $27.5\Omega$ and the power dissipated across each bulb is $6.875\text{W}$ .