$$\text { Figure } 14

Question

$$\text { Figure } 14 < 1$$
-In Figure 14-1, the primary to secondary turns ratio is changed to 2.5:1 and the secondary current equals  100 mA . What is the reflected resistance seen by the primary?
A) 3 $\mathrm { k } \Omega$ 
B) 5 $\mathrm { k } \Omega$ 
C) 1.2 $\mathrm { k } \Omega$ 
D) 2.5 $k \Omega$

Quizplus · Accepted Answer

The reflected resistance seen by the primary can be calculated using the formula $R_p = R_s \times (N_p/N_s)^2$, where $R_p$ is the reflected resistance on the primary side, $R_s$ is the resistance on the secondary side, $N_p/N_s$ is the turns ratio from primary to secondary. Given the secondary current is 100 mA and the turns ratio is 2.5:1, without the secondary resistance directly, we can infer the transformation effect of the turns ratio on impedance. A 2.5:1 ratio increases the impedance seen on the primary by the square of the ratio, which is $2.5^2 = 6.25$. Without the exact secondary resistance value, we focus on the effect of the turns ratio. The closest answer reflecting a significant increase in impedance due to the turns ratio is 3 kΩ, assuming a base resistance value on the secondary that when multiplied by 6.25 gives a result closest to one of the provided options.

Figure 14<1\text { Figure } 14 < 1 Figure 14<1 -In Figure 14-1, the Primary to Secondary Turns Ratio Is

$\text { Figure } 14 < 1$ -In Figure 14-1, the Primary to Secondary Turns Ratio Is