C. an electrical juncture of the terminals of two or more devices, …a path formed by tracing through a sequence of devices without passing through any node more than once.

D. an electrical juncture of the terminals of two devices, …a path formed by tracing through a sequence of devices without passing through any node more than once.

E. a juncture of the terminals of two devices, …a path formed by tracing through a sequence of devices without passing through any node more than once.

 

Solution:

A node is an electrical juncture of the terminals of two or more devices, but loop is a path formed by tracing through a sequence of devices without passing through any node more than once.

Answer: C.

2. Circuit consists of two parallel branches. Current through the branch, whose resistance equals to

5 Ω is 3A. What is the second branch current, whose resistance is 2 Ω?

A. 7.5A B.5A C. 10A D.9A E. 4A

 

Solution:

The voltage across the upper branch is V=3*5=15V.

The same voltage is applied to the lower branch, so the current in it can be found by Ohm’s Law: I=V/R=15/2=7.5A

 

 

Answer: A.

3. Circuit consists of two parallel branches. Current through the branch, whose resistance equals to

5 Ω is 3A. What power is absorbed by the second branch, whose resistance is 2 Ω?

A. 175.5W B.155W C. 100W D.112.5W E. 144W

Solution:

The voltage across the upper branch is V=3*5=15V.

The voltage across the lower branch is the same (parallel arrangement), so the power is P=VI=V²/R=225/2=112.5W

 

 

Answer: D.

4. Current of the current source is equal to 3mA. Resistance, connected in parallel with the source, is equal to 10 kΩ. In process of source transformation we defined that voltage of the equivalent voltage source is equal to ____ V.

A. 20 B. 30 C. 40 D. 50 E. 60

 

Solution:

V=IR=3*10^-3*10*10³=30V