# Basic Electrical Engineering 3

First Year Engineering Common to all Branches: Basic Electrical Engineering 3

Subject: Basic Electrical Engineering 3

Part 3: List for questions and answers of Basic Electrical Engineering

Q1. A given power supply is capable of providing 6 A for 3.5 h. Its ampere-hour rating is
a) 0.58 Ah
b) 2.1 Ah
c) 21 Ah
d) 58 Ah

Q2. If you used 400 W of power for 30 h, you have used
a) 1.3 kwh
b) 13.3 kwh
c) 1.2 kwh
d) 12 kwh

Q3. A 6 V battery is connected to a 300 load. Under these conditions, it is rated at 40 Ah. How long can it supply current to the load?
a) 1 h
b) 200 h
c) 2,000 h
d) 10 h

Q4. In 40 kw, there are
a) 0.4 mw
b) 40,000 W
c) 400 W
d) 5,000 W

Q5. If you used 600 W of power for 60 h, you have used
a) 36 kwh
b) 3.6 kwh
c) 10 kwh
d) 1 kwh

Q6. If it takes 400 ms to use 12,000 J of energy, the power is
a) 30 kw
b) 30 W
c) 3 W
d) 300 kw

Q7. For 12 V and 40 ma, the power is
a) 480 mw
b) 0.480 W
c) 480,000 μw
d) All of the above

Q8. A half-watt is equal to how many milliwatts?
a) 5,000 mw
b) 5 mw
c) 500 mw
d) 50 mw

Q9. Three hundred joules of energy are consumed in 15 s. The power is
a) 2,000 W
b) 2 W
c) 20 W
d) 200 W

Q10.How much continuous current can be drawn from a 60 Ah battery for 14 h?
a) 42.8 A
b) 428 A
c) 4.28 A
d) 4.2 A

Q11. What kva rating is required for a transformer that must handle a maximum load current of 8 A with a secondary voltage of 2 kv?
a) 4 kva
b) 0.25 kva
c) 16 kva
d) 8 kva

Q12. When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is
a) 12 V
b) 120 V
c) 240 V
d) 2,400 V

Q13. A certain transformer has 400 turns in the primary winding and 2,000 turns in the secondary winding. The turns ratio is
a) 0.2
b) 0.4
c) 5
d) 25

Q14. The primary winding of a transformer has 110 V ac across it. What is the secondary voltage if the turns ratio is 8?
a) 8.8 V
b) 88 V
c) 880 V
d) 8,800 V

Q15. To step 110 V ac down to 20 V ac, the turns ratio must be
a) 5.5
b) 18
c) 0.18
d) 0.018

Q16. If 25 W of power are applied to the primary of an ideal transformer with a turns ratio of 10, the power delivered to the secondary load is
a) 25 W
b) 0 W
c) 250 W
d) 2.5 W

Q17. In a certain loaded transformer, the secondary voltage is one-fourth the primary voltage. The secondary current is
a) One-fourth the primary current
b) Four times the primary current
c) Equal to the primary current
d) One-fourth the primary current and equal to the primary current

Q18. A certain transformer has a turns ratio of 1 and a 0.85 coefficient of coupling. When 2 V ac is applied to the primary, the secondary voltage is
a) 1.7 V
b) 0.85 V
c) 1 V
d) 0 V

Q19. The primary winding of a power transformer should always be
a) Open
b) Shorted
c) Switched
d) Fused

Q20. To step 120 V ac up to 900 V ac, the turns ratio must be
a) 75
b) 750
c) 7.5
d) 0.13

Part 3: List for questions and answers of Basic Electrical Engineering