17. A 120 V lamp-dimming circuit is controlled by a rheostat and protected from excessive current by a 3 A fuse. To what minimum resistance value can the rheostat be set without blowing the fuse? Assume a lamp resistance of 20 ohms.
(a) 40 Ω (b) 4 Ω (c) 2 Ω (d) 20 Ω
Answer : (d)
Explanation : No answer description available for this question. Let us discuss.
5555555555 9. A 47 Ω resistor and a capacitor with 150 Ω of capacitive reactance are in series across an ac source. The impedance, expressed in rectangular form, is ________. (a) Z = 47 Ω + j150 Ω (b) Z = 47 Ω – j150 Ω (c) Z = 197 Ω (d) Z = 103 Ω
5555555555 6. A 15 Ω resistor, an inductor with 8 Ω inductive reactance, and a capacitor with 12 Ω capacitive reactance are in parallel across an ac voltage source. The circuit impedance is ________. (a) 12.7 Ω (b) 127 Ω (c) 4,436 Ω (d) 6,174 Ω