This is the Multiple Choice Questions Part 6 of the Series in DC Circuits as one of the Electrical Engineering topic. In Preparation for the REE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Exam Questions in Electrical Engineering field, Electrical Engineering Books, Journals and other Electrical Engineering References.
Continue Practice Exam Test Questions Part 6 of the Series
OHM’S LAW AND ELECTRIC CIRCUITS
Choose the letter of the best answer in each questions.
⇐ MCQ in DC Circuits Part 5 | REE Board Exam
251. Which of the following statement is TRUE both for a series and parallel d.c circuit?
A. powers are additive
B. voltages are additive
C. current additive
D. elements have individual currents
Answer: Option A
Solution:
252. A 100-W, 110-V and a 50-W lamp are connected in series across a 220-V dc source. If the resistances of the two lamps are assumed to remain constant, the voltage across the 100-W lamp is ____ volt.
A. 110
B. 73.3
C. 146.7
D. 220
Answer: Option A
Solution:
253. In the parallel circuit of Fig.1.3, the value of V0 is _____ volt.
A. 12
B. 24
C. 0
D. -12
Answer: Option C
Solution:
254. In the series circuit of Fig 1.4, the value of V0 is ____ volt.
A. 12
B. -12
C. 0
D. 6
Answer: Option D
Solution:
255. In Fig 1.5, there is a drop of 20 V on each resistor. The potential of point A would be ____ volt.
A. +80
B. -40
C. +40
D. -80
Answer: Option C
Solution:
256. From the voltmeter reading of Fig. 1.6, is it obvious that
A. the 3 Ω resistor is short circuited
B. the 6 Ω resistor is short circuited
C. nothing is wrong with the circuit
D. the 3 Ω resistor is open-circuited
Answer: Option D
Solution:
257. With reference to Fig 1.7, which of the following statement is true?
A. E and R1 form a series circuit
B. R1 is in series with R3
C. R1 is in series with R2
D. there is no series circuit
Answer: Option A
Solution:
258. Which of the following statements is correct concerning the Fig. 1.8?
A. R2 and R3 form a series of path
B. E is in series with R1
C. R1 is in parallel in R3
D. R1, R2 and R3 form a series of circuit
Answer: Option B
Solution:
259. What is the equivalent resistance in ohms between points A and B of Fig. 1.9? All resistances are in ohms.
A. 12
B. 14.4
C. 22
D. 2
Answer: Option D
Solution:
260. What do you call a resistor that does not obey Ohm’s Law?
A. Potentiometer
B. Carbon-Film Resistor
C. Wire-Wound Type
D. Non-linear Resistor
Answer: Option D
Solution:
261. A 100 W, 110 V and 50 W, 110 V lamps are connected in series across a 220 V DC source. If the resistances of the two lamps are assumed to remain constant, the voltage across the 100 W lamp is _____ volt?
A. 110 V
B. 73.3 V
C. 146.7 V
D. 220 V
Answer: Option B
Solution:
262. A potential divider of resistance of 50 ohms is connected across a 100 V DC source. A load resistance of 10 ohms is connected across a tap in the potential divider and the negative terminal of the source. If a current of 4 A flows towards the load, what is the current supplied by the source?
A. 5.32 A
B. 5.05 A
C. 5.21 A
D. 5.48 A
Answer: Option B
Solution:
263. Two resistors A and B made of different materials have temperature coefficients of resistance at 20°C of 0.004 and 0.006 respectively. When connected across a voltage source at 20°C, they draw current equally. What percentage of the total current at 100°C does resistor A carry?
A. 47.14%
B. 52.86%
C. 61.34%
D. 38.66%
Answer: Option B
Solution:
264. A conductor has a resistance of 7 ohms at 0°C. At 20°C, the resistance has become 7.5 ohms. Calculate the temperature coefficient of the conductor at 20°C.
A. 1/300 /°C
B. 1/400 /°C
C. 1/500 /°C
D. 1/600 /°C
Answer: Option A
Solution:
265. Which of the following is a non-linear element?
A. diode
B. heater coil
C. transistor
D. electric arc with unlike electrode
Answer: Option A
Solution:
ELECTRICAL AND HEAT ENERGY
266. EE Board Exam April 1992
An electric kettle was marked 500 W, 230 V found to take 15 minutes to bring 1 kilogram of water at 15°C to boiling point. Determine the heat efficiency of the kettle.
A. 79.1%
B. 75.3%
C. 72.4%
D. 74.8%
Answer: Option A
Solution:
267. REE Board Exam October 1997
A process equipment contains 100 gallons of water at 25°C. It is required to bring it to boiling in 10 minutes. The heat loss is estimated to be 5%. What is the kW rating of the heater?
A. 125 kW
B. 252 kW
C. 50.5 kW
D. 207 kW
Answer: Option D
Solution:
268. EE October 1989
A total of 0.8 kg of water at 20°C is placed in a 1-kW electric kettle. How long a time in minute is needed to raise the temperature of the water to 100°C?
A. 4.46 min
B. 5.32 min
C. 5.34 min
D. 4,.56 min
Answer: Option A
Solution:
269. REE October 1998
How many calories does an electric heater of 100 watts generate per second?
A. 10
B. 1000
C. 23.88
D. 42.25
Answer: Option C
Solution:
270. REE Board Exam October 1997
The electric energy required to raise the temperature of water in a pool is 1000 kWh. If the heat losses are 25%, the heating energy required will be ______.
A. 1111 kWh
B. 1266 kWh
C. 1750 kWh
D. 1333 kWh
Answer: Option D
Solution:
271. EE Board Exam April 1992
An electric heater carries 12 A at 110 V, is submerged in 22.5 lbs of water for 30 minutes. What will be the final temperature of the water if its initial temperature is 35°F?
A. 135.43°F
B. 125.42°F
C. 133.56°F
D. 128.33°F
Answer: Option A
Solution:
272. EE Board Exam October 1990
In an electric heater the inlet temperature is 15°C. Water is flowing at the rate of 300 grams per minute. The voltmeter measuring voltage across the heating element reads 120 volts and an ammeter measuring current taken reads 10 amperes. When steady state is finally reached, what is the final reading of the outlet thermometer?
A. 57.6°C
B. 68.4°C
C. 72.6°C
D. 42.6°C
Answer: Option C
Solution:
273. EE Board Exam October 1991
Four cubic meters of water is to be heated by means of four 1.5 kW, 230-V immersion heating elements. Assuming the efficiency of the heater as 90%, determine the time required in boiling the water if the initial temperature is 20°C and if all four elements are connected in parallel.
A. 71 hrs
B. 63 hrs
C. 69 hrs
D. 66 hrs
Answer: Option C
Solution:
274. EE Board Exam October 1991
Four cubic meters of water is to be heated by means of four 1.5 kW, 230-V immersion heating elements. Assuming the efficiency of the heater as 90%, determine the time required in boiling the water if the initial temperature is 20°C and if the elements are connected two in series in parallel with two in series.
A. 275.6 hrs
B. 295.3 hrs
C. 252.2 hrs
D. 264.4 hrs
Answer: Option A
Solution:
275. REE Board Exam September 2001
How many joules per second are then in 10 watts?
A. 10
B. 5
C. 20
D. 24.5
Answer: Option A
Solution:
276. REE Board Exam September 2001
1013 ergs/sec is equal to how many kilowatts?
A. 1,000
B. 250
C. 100
D. 10
Answer: Option A
Solution:
277. REE Board Exam September 2000
What is 1 kW-hr in BTU?
A. 4,186
B. 3,413
C. 746
D. 1,000
Answer: Option B
Solution:
278. REE Board Exam October 1998
What is the work in ergs needed to raise a 10 g weight 100 m up?
A. 4.9 x 105
B. 9.8 x 107
C. 98 x 107
D. 1.96 x 107
Answer: Option B
Solution:
279. REE Board Exam October 1999
The quantity of heat required to raise the temperature of water by 1°C.
A. energy
B. specific heat
C. calorie
D. BTU
Answer: Option C
Solution:
280. REE Board Exam October 1999
When heat is transferred into any other form of energy or when other forms of energy are converted into heat, the total amount of energy is constant. This is known as
A. First law of thermodynamics
B. Boyle’s law
C. Specific heat
D. Isothermal expansion
Answer: Option A
Solution:
281. REE Board Exam September 2002
What is 1012 ergs/sec in kW?
A. 100 kW
B. 1,000 kW
C. 10 kW
D. 10,000 kW
Answer: Option A
Solution:
282. REE Board Exam October 2000
An electric heater is used to heat up 600 grams of water. It takes 14 minutes to raise the temperature of water by 40°C. If the supply voltage is 220 volts, what is the power rating of the heater neglecting heat losses?
A. 180 W
B. 120 W
C. 200 W
D. 60 W
Answer: Option B
Solution:
283. REE Board Exam April 2001
A 100 liter of water is heated from 20°C to 40°C. How many kWHR of electricity is needed assuming no heat loss?
A. 4.2
B. 2.3
C. 5.6
D. 3.7
Answer: Option B
Solution:
284. REE Board Exam April 2002
Ten (10) kW is equal to ____ gram-cal/sec.
A. 156
B. 436
C. 2,388
D. 425
Answer: Option C
Solution:
285. ECE Board Exam November 1995
Two heaters A and B are in parallel across supply voltage V. Heater A produces 500 kcal in 20 minutes and B produces 1000 kcal in 10 minutes. The resistance of A is 10 ohms. What is the resistance of B, if the same heaters are connected in series voltage V?
A. 4.5 ohms
B. 2.5 ohms
C. 4.5 ohms
D. 0.14 ohm
Answer: Option B
Solution:
286. In the SI system of units, the unit of force is
A. kg-wt
B. Newton
C. Joule
D. N-m
Answer: Option B
Solution:
287. The basic unit of electric charge is
A. ampere-hour
B. watt-hour
C. coulomb
D. farad
Answer: Option C
Solution:
288. The SI unit of energy is
A. Joule
B. kWh
C. kcal
D. m-kg
Answer: Option A
Solution:
289. The SI unit of energy is
A. Joule
B. kWh
C. kcal
D. m-kg
Answer: Option A
Solution:
290. Two heating elements, each of 230-V, 3.5 kW rating are first joined in parallel and then in series to heat same amount of water through the same range of temperature. The ratio of the time taken in the two cases would be
A. 1:2
B. 2:1
C. 1:4
D. 4:1
Answer: Option C
Solution:
291. If a 220 V heater is used on 110 V supply, heat produced by it will be ____ as much
A. one-half
B. twice
C. one-fourth
D. four times
Answer: Option C
Solution:
292. For a given line voltage, four heating coils will produce maximum heat when connected
A. all in parallel
B. all in series
C. with two parallel pairs in series
D. one pair in parallel with the other two in series
Answer: Option A
Solution:
293. The electric energy required to raise the temperature of a given amount of water is 1000 kWh. If heat losses are 25%, the total heating energy required is ____ kWh.
A. 1500
B. 1250
C. 1333
D. 1000
Answer: Option C
Solution:
294. One kWh of energy equals nearly
A. 1000 W
B. 860 kcal
C. 4186 J
D. 735.5 W
Answer: Option B
Solution:
295. A force of 10,000 N accelerates a body to velocity 0.1 km/s. The power developed is ____ kW.
A. 1,000,000
B. 36,000
C. 3600
D. 1000
Answer: Option D
Solution:
296. A 100 W light bulb burns on an average of 10 hours a day for one week. The weekly consumption of energy will be ____ unit/s.
A. 7
B. 70
C. 0.7
D. 0.07
Answer: Option A
Solution:
297. Two heaters, rated at 1000 W, 250 volts each, are connected in series across a 250 volt, 50 Hz A.C. mains. The total power drawn from the supply would be ____ watt.
A. 1000
B. 500
C. 250
D. 2000
Answer: Option B
Solution:
298. One watt is equal to ____.
A. 4.19 cal/sec
B. 778 BTU/sec
C. 107 ergs/sec
D. 10-7 ergs/sec
Answer: Option C
Solution:
299. The current in an electric lamp is 5 amperes. What quantity of electricity flows toward the filament in 6 minutes?
A. 30 C
B. 3600 C
C. 72 C
D. 1800 C
Answer: Option D
Solution:
300. An electric heater is rated at 120 volts, 1000 watts and is used to boil water. Calculate the time in minutes to raise the temperature of 1 liter of water from 15°C to boiling. The heater has an over-all efficiency of 92%.
A. 6.4 minutes
B. 5.4 minutes
C. 4.4 minutes
D. 3.4 minutes
Answer: Option A
Solution:
⇒ MCQ in DC Circuits Part 7 | REE Board Exam
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