Answer: D. A. The sum of currents at a node is 0
3. KCL states that A. The sum of currents at a node is 0. B. the sum of currents in a loop is 0. C. The algebraic sum of currents at a node is 0. D. The algebraic sum of currents in a loop is 0. E. The algebraic sum of currents at a node is 0 at every instant.
Solution: Kirchhoff’s current law (KCL) is based on the principle of conservation of charge and states that the algebraic sum of currents at a node is 0 for every instant. Answer: E.
4. The unit of current is A. V B. J C. A D. F E. C
Solution: Current is defined as dq/dt and is a measure of the flow of electrical charge. The unit of current is Ampere (A). 1 A = 1 Coulomb/second. Answer: C.
5. We know RA, RB, and RC for delta. What is R2 for delta-to-star transformation? (see Fig. 1). A. R2 = (RA + RB + RC)/ RA B. R2 = RBRC/ (RA + RB + RC) C. R2 = RARC/ (RA + RB + RC) D. R2 = RBRA/ (RA + RB + RC) E. R2 = RBRC/ (RA + RB)
Fig.1
Solution:
Answer: C.
A. 2A B. – 1A C. 5A D. 1A E. – 2A
Solution: Both current sources are directed in the same direction, so the resulting current source will be presented as the sum I=2+3=5A. Answer: C.
Fig. 2 7. Define VA for the circuit in Fig.3. VA= A.VS*R4/(R1+R4) B. VS*R2/(R1+R4) C. VS*R3/(R1+R4) D. VS*R3/(R1+R3) E. VS*R4/(R1+R3)
By Voltage Division Rule:
Answer: D.
Fig.3
8. For the circuit in Fig.4 define V0. Fig.4
Solution: Equivalent circuit will be
Now by Voltage Division Rule we have
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6. What is the value of current I? (see Fig.2)
Solution:
A. 12V B.6V C.4V D.3V E. 10V
V
