Answer:
EMF of the power source, E = 19.34 volts
Step-by-step explanation:
It is given that,
Voltage at which computer sensor is operated, V = 11.7 V
Power, P = 26.37 W
Total resistance of the power source, R = 2.23 Ohms
Firstly, calculating the current in the circuit. It is calculated as :
![P=I^2R](https://img.qammunity.org/2020/formulas/physics/high-school/f35m14q57qc21dskkjzvdygp4lfysp391s.png)
![I=\sqrt{(P)/(R)}](https://img.qammunity.org/2020/formulas/physics/college/a8uxcwx56xbnj290mpic3n663z6x671x6k.png)
![I=\sqrt{(26.37)/(2.23)}](https://img.qammunity.org/2020/formulas/physics/college/fpa7vtrweyqqfih5tjrv618b8is5u59s8z.png)
I = 3.43 A
Let E is the emf of the power source. It is given by,
![E=V+IR](https://img.qammunity.org/2020/formulas/physics/college/8yeggddobgwz8y65j438wr603d3rm1vntn.png)
![E=11.7+3.43* 2.23](https://img.qammunity.org/2020/formulas/physics/college/ewdhoam2f20611qczeeyycp3crpg93lfk5.png)
E = 19.34 volts
Hence, the EMF of the power source is 19.34 volts. Hence, this is the required solution.