Basic Electrical Flashcards
7 cards from real BEE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Basic Electrical flashcards as text
A sinusoidal voltage v(t) = 170 sin(377t) V. What is the RMS value?
Answer: 120.2 V
V_rms = V_peak / √2 = 170 / 1.414 ≈ 120.2 V.
The time constant of an RC series circuit with R = 2 kΩ and C = 50 μF is:
Answer: 0.1 s
τ = RC = 2000 × 50×10⁻⁶ = 0.1 s.
In a purely capacitive AC circuit, the current leads the voltage by:
Answer: 90°
In a purely capacitive circuit, the current leads voltage by 90° (or π/2 radians).
Which of the following quantities is measured in Siemens?
Answer: Conductance
Conductance (G = 1/R) is measured in Siemens (S), the reciprocal of ohms.
Two identical 12 V batteries with internal resistance 1 Ω each are connected in series. What is the total EMF and total internal resistance?
Answer: 24 V, 2 Ω
Series connection adds EMFs (12+12=24 V) and internal resistances (1+1=2 Ω).
What is the frequency of the AC supply in the expression v(t) = 100 sin(314t + 30°) V?
Answer: 50 Hz
ω = 314 rad/s, so f = ω/(2π) = 314/6.28 ≈ 50 Hz.
Thevenin's theorem replaces a complex network with:
Answer: A voltage source in series with a resistance
Thevenin's theorem states any linear network can be replaced by V_th in series with R_th.