1
UNIVERSITY OF TECHNOLOGY
ELECROMECHNICAL DEPARTMANT
SYSTEMS BRANCH
Dr. Sameir Abd Alkhalik Aziez
1. (Figure 1) Find the equivalent resistance between terminals A and B if
each of the resistances is 5 ohms. (3.09 ohms)
2. (2) Find the equivalent resistance between A end B. (15.11 ohms)
3. (3) Find the equivalent resistance between A & B. Also find the current
in the 6 ohm resistor when the applied voltage is 70 V. (14 ohms; 1.25 A)
4. (4) Find the current I. (32.26 A)
5. (5) Find the voltage V. (60 V)
6. (6) Find the current I. (2.41 A)
7. (7) Show that V =E (R
1
/ ( R
1
+ R
2
)- R
3
/ ( R
3
+ R
4
)) ; also show that
V = 0 when R
4
= R
2
R
3
/ R
1
.
8. (8) Find the current I.
(12.07 A)
9. (9) Find the equivalent resistance between A & B. (250 ohms)
10. (10) Find the equivalent resistance between;
A & C when B & D ere free;
(( R
1
+R
4
) // ( R
2
+ R
3
) ;
A & C when B & D are shorted to each other;
( R
1
//R
2
) + ( R
3
// R
4
) ;
B & D when A & C are free;
( R
1
+R
2
) // ( R
3
+ R
4
) ;
B & D when A & C ere shorted to each other;
( R
1
//R
4
) + ( R
2
// R
3
) ;
A & B when C & D ere free;
R
2
// ( R
1
+ R
3
+ R
4
) ;
A &. B when C & D are shorted to each ether.
R
2
// ( R
1
+ R
3
)) .
11. A voltmeter gives a full-scale reading of 30 V. It resistance is 2
K-ohms. How can it be made to measure 75V? (series multiplier of 3
K-ohms).
12. An ammeter gives a full-scale reading of 250 mA. Its resistance is
0.37 ohms.
How can it be made to measure 2 A? (meter shunt of 52.9
m-ohms)
13. A millivoltmeter has a range of 100 mV. Its internal resistance is 5
ohms. What value of shunt resistance allows it to be used as an ammeter
FIRST YEAR ELECTROMECHNICAL
ENGINEERING
BASICS ELECRICAL ENGINEERING
Question Sheet (3)
2
of range 50 A? What is the current per division if the scale has 100
divisions?
(2 m-ohms; 0.5 A)
14. (1l) Find the equivalent resistance between A & B.
15. (12) Find the equivalent resistance between A & B.
16. (13) Find the equivalent resistance between A & B.
17. (l4) Find, the power dissipation in the 6 ohm resistor. (8.64 W )
18. (15) Find, the power dissipation in the 6 ohm resistor. (2.17 W )
19.(16) Find the equivalent resistance between A & B if P is a connection
point. (R)
20.(16) Find the equivalent resistance between A & B if there is only
cross-over at P. (R).
21. Three resistors of 50, 100,
and 150 ohms are connected in star.
Find the equivalent delta. (550, 275, 183.3 ohms)
22. Three resistors of 20, 30, and 50 ohms are connected in delta. Find the
equivalent star. (15, 10, 6 ohms)-
23. (17) Find the equivalent resistance between A & B. (6 ohms)
24. (18) Find the equivalent resistance between A & B. (10.7 ohms)
25. (19) Find the equivalent resistance between A & B. (4.5 ohms)
26. (20) Find the equivalent resistance between A & B. (4.93 ohms)
27.(21) find the equivalent resistance between A & B. (2.05 ohms)
28. (22) Find the current in the 8.5 ohm resistor. (1.28 A)
29. (23) Find the current in the 2 ohm resistor. (1.37 A)
30. (24) Find the source current. (2.15 A)
31. (25) Find the voltage- across the 3 ohm resistor. (0.79 V)
32. (26) Find the equivalent resistance between A & B . (36 ohms)
33. (27) Find the source current. (2.19 A)
34. (28) Find the source currents. (1.12 A; 4.70 A)
35. (29) Find the- source currents. (7.27 A; 5.64 A)
NB: In the circuit diagrams, all resistance values are in ohms .
3
2
3
8
7
4
9
10
5
1
6
4
12
14
٤
19
17
15
٥
20
21
16
٦
13
٣
18
11
9
5
22
23
28
27
24
26
29
25