Circuite Electrice - Probleme

E.1 Probleme Cir El c.c.: Kirchhoff, Putere şi Energie

Q.1 Determine the current i in the following circuit.

2 3

2

i

3 4

5

8 6

All units in

V, A,Ω

4

9

5

Q.2 Determine the current i and the voltage v in the following circuit for R = 2Ω and

R = 50KΩ.

Adascalitei, Probleme 197

Network

A

Network

R B

A

i

10V

5

v

Q.3 Determine the source voltage v and the voltage across the 3Ω resistor in the

following circuit.

1Ω

3Ω

4 A

v

Ω

4Ω 4Ω

2

4Ω

Q.4 The Ammeter AM and voltmeter VM, connected as shown below, measure

current and voltage, respectively. The ammeter will give a positive reading if the

current flowing into its "+" terminal is positive.

+ −

AM

+ −

VM

Electrical device

A B

Determine if the electrical device is consuming or supplying power when

(a) both meters give positive readings;

(b) both meters give negative readings; and

(c) one meter gives a positive reading while the other gives a negative

reading.

(d) one meter or both meters give zero readings.

Q.5 Determine the current in the following circuit.

Adascalitei, Probleme 198

V

Ω Ω

15 5 V

4 1

How much power is each component consuming or supplying?

Q.6 Determine the voltages and currents in the following circuit.

A

Ω

A Ω

4

10 6 5

Is the 10A current source consuming or supplying power?

Q.7 In the following system, determine the efficiency of the motor and the torque on

the fan shaft?

V

A

DC

power

supply

DC

motor

Fan load

2.5 h.p.

100 rev/min

20

100

How much energy is lost in the motor per minute? (Note that 1h.p. = 746W.)

Q.8 In the following system, the efficiency of the generator is 0 9

CIRCUITE ELECTRICE -PROBLEME(english) SEMINAR