EE - DC CIRCUITS [PL] RQ

What is the basis for declaring the direction of electric current is from positive terminal to negative terminal of a circuit?

A. Scientific

B. Superposition

C. Conventional

D. Tradition

C. Conventional

Which of the following will the effect of the electric shock in the human body depends on

A. Voltage flowing in the body

B. Current flowing in the body

C. Line Power

D. Resistance in the line

B. Current flowing in the body

Which of the following conductors has the highest resistance?

A. Manganin

B. Nichrome

C. Constantan

D. Steel

B. Nichrome

In American wire gauge (AWG) as the number gage increase the wire diameter?

A. increase

B. decrease

C. does not change

D. does change

B. decrease

What is the value of the resistor with color coded Green-Blue-Red-Gold?

A. 56,000 ohm +10%

B. 56,000 ohm +5%

C. 5,600 ohm + 10%

D. 5,600 ohm +5%

D. 5,600 ohm +5%

A copper bar is ½ inch by 4 inches by 20 feet. If the resistivity of the copper bar is 10.37 ohms-cmf. What is the resistance of the copper bar?

A. 17. 3 x10-50hm

B. 8.15 x10-50hm

C. 0.0052 ohm

D. 125 ohms

B. 8.15 x10-50hm

A cylindrical copper rod has a resistance R. It is reformed to twice its original length with NO change in volume. What is the new resistance?

A. 4R

B. 2R

C. 6R

D. 8R

A. 4R

Nine identical wires, each of diameter d and length L, are connected in series. The combination has the same resistance as a single similar wire of length L but whose diameter is

A. 3а

B. d/3

C. 9d

D. d/9

B. d/3

A heating element consists of two wires of different materials connected in series. At 20°C. they have resistances of 600 ohms and 300 ohms, and average temperature coefficients of 0.001 1/°C and 0.004 1PC, respectively. What is the heating element's total resistance at 50°C?

A. 904 ohms

B. 954 ohms.

C. 984 ohms

D. 994 ohms

B. 954 ohms

A 100-Volt carbon filament lamp takes 1 Amp when glowing with a filament temperature of 1615°C. Calculate the momentary current when the lamp is first switched on in air temperature of 15°C. The temperature coefficient of resistance for carbon may be taken as -0.000265 per °C at 15°C .

A. 1.72 Amp

B. 0.65 Amp

C. 0.58 Amp

D. 1.94 Amp

C. 0.58 Amp

A dc motor 120 Volts has 100 Amp rated current, The allowable voltage drop of 3% of input voltage. Find the maximum distance from the supply if the wire has a diameter of 316 mils and resistivity of wire is 10.4 ohm-cmf.

A. 508 ft

B. 316 ft

C. 178 ft

D. 203 ft

C. 178 ft

Suppose that the fundamental dimension are taken to be force (F), velocity (V) and time (T). What are the dimension of potential energy?

A. FVT

C. FV/T

B. F/T

D. F/T2

A. FVT

Resistor 1 has twice the resistance of resistor 2. They are connected in parallel to a battery. Find the ratio of thermal energy generation rate in resistor 1 to that of resistor 2.

A. 2:1

B. 1:2

C. 4:1

D. 1:4

B. 1:2

A to-ohm resistor is connected in parallel with a series combination of resistors of 8 ohms and 12 ohms. If the voltage drop across the 8-ohm resistor is 48 Volts, what is the current in Amp?

A. 16

B. 18

C. 22

D. 20

A. 16

A 20-ohm resistor is connected in parallel with a variable resistor R. The parallel combination is then connected in series with a 4-ohm resistor and connected across a 240 V source. Determine the minimum value of R if the power of R is equal to the power taken by the 4-ohm resistor.

A. 7.95 ohms

B. 8.40 ohms

C. 7.64 ohms

D. 6.87 ohms

C. 7.64 ohms

Find the work in kWh to lift 1 ton at a height of 55 ft for 10 sec. The motor gear efficiency is 51%.

A. 0.083

B. 83

C. 0.83

D. 830

A. 0.083

A process equipment contains 100 gallons of water at 25°C. It is required to bring it to boiling point in 10 minutes. The heat loss is estimated to be 5%. What is the kW rating of the heater?

A. 125

B. 252

C. 50.5

D. 207

D. 207

A car battery is rated at 80 amp-hr. An ampere-hour is a unit of ______

A. Power

B. Charge

C. Energy

D. Current

B. Charge

A 12-Volt battery has 50 Amp-hr. capacity. The internal resistance is 0.1 ohm. A 5-ohm resistor is connected for 5 hours. How many Amp-hours are still left?

A. 38.23

B. 3

C. 41.24

D. 11.76

A. 38.23

What is the power absorbed by 900-ohm resistor in the network shown below (Fig.1)?

A. 3.52 Watts

B. 1.44 Watts

C. 5.43 Watts

D. 4.84 Watts

B. 1.44 Watts

Twelve resistances 1 ohm each are arranged along the edge of a cube with junctions at corners What resistance will be measured between terminals of symmetrically opposite comers of the cube?

A. 6/5-ohm

B. 5/6-ohm

C. 5/9-ohm

D. 6/111-ohm

B. 5/6-ohm

Superposition theorem can be applied only to circuits having ______

A. resistive elements

B. linear bilateral elements

C. non-linear elements

D. passive elements

B. linear bilateral elements

"In any linear bilateral network, if a source of emf E in any branch produces a current I in any other branch, then same emf acting in second branch would produce the same current 1 in the first branch". The above statement is associated with.

A. compensation theorem

B. reciprocity theorem

C. superposition theorem

D. Millman's theorem

B. reciprocity theorem

If an electrical network having one or more voltage source, is transformed into equivalent electrical network with single voltage source (which is short circuit current of previous circuit with parallel internal resistance of the network with all current source replaced by their internal resistance. The above illustration is called ______.

A. Thevenin's Theorem

B. Norton's Theorem

C. Superposition Theorem

D. Compensation Theorem

B. Norton's Theorem

Two-24 Volt battery supply power to a 10-ohm load. One battery has 0.2-ohm internal resistance. While the other has 0.4 ohm. What is the load voltage and power does this load draws?
A. 23.84 Volts & 56.8 Watts

B. 24 Volts & 48.2 Watts

C. 23.68 Volts & 56.1 Watts

D. 23.24 Volts & 60.8 Watts

C. 23.68 Volts & 56.1 Watts

From the given network shown in Fig. 2, determine the respective current supplied by the 10-Volt,

12-Volt, and 24-Volt batteries.

A 1.5 Amp, -1.9 Amp, 2.2 Amp

C. -1.5 Amp, 1.9 Amp, 2.2 Amp

B. -2.2 Amp, 1.9 Amp, -1:5 Amp

D. 1.5 Amp, 1.9 Amp, -2.2 Amp

D. 1.5 Amp, 1.9 Amp, -2.2 Amp

Find the current flowing in the 4-ohm resistor in the network shown using Thevenin's theorem Fig.3

А. - 0.333 Amp

B. - 2.33 Amp

C. 1.522 Amp

D. 1.667 Amp

D. 1.667 Amp

A barangay power station supplies 60KW to a load over 2,500 ft, 100 sq mm, 2 conductor copper feeders, the resistance of which is 0.078 ohm per 1000 ft. The busbar voltage is maintained at 600 V. Determine the maximum power which can be transmitted.

A. 473.7 kW

B. 230.77 kW

C. 60 kW
D. 384 kW

B. 230.77 kW

The Norton equivalent of a circuit consists of a 2 Amp current source in parallel with a 4-ohm resistor. Thévenin's equivalent of this circuit is a ______ Volt source in series with a ______ ohm resistor,

A. 8.4

В. 0.5 2

C.6,4

D. 2,2

A. 8.4

In Flemming's Right Hand Rule, which finger point the direction of current?

A. Thumb

B. Index

C. Middle

D. Ring

C. Middle

The magnetic torque exerted on a flat current-carrying loop of wire by a uniform magnetic field "B” is ______

A. maximum when the plane of the loop is perpendicular to "B”

B. independent of the orientation of the the loop

C. maximum when the plane of the loop is parallel to "B”

D. dependent on the shape of the loop for a fixed loop area

C. maximum when the plane of the loop is parallel to "B”

The unit of magnetic dipole moment are ______

A. ampere/meter²

B. ampere-meter

C. ampere-meter²

D. ampere/meter

C. ampere-meter²

A substance or material having relative permeability of less than unity is classified as:

A. ferro-magnetic

B. dia-magnetic

C. para-magnetic

D. none of these

B. dia-magnetic

Permeability in a magnetic circuit corresponds to

in an electric circuit.

A. resistance

B. resistivity

C. conductivity

D. conductance

C. conductivity

The direction of induced e.m.f. can be found by ______

A. Laplace's law

B. Lenz's law

C. Fleming's right-hand rule

D. Kirchhoff's voltage law

B. Lenz's law

In electromagnetic induction three of the following terms are identical. Name the ONE that is NOT.

A. flux

B. Maxwell per sq. cm

C. lines per sq. cm

D. Gauss

A. flux

Which of the following statements is TRUE for steady-state conditions in a circuit powered by a dry cell?

A. Voltage is dependent upon time

B. Inductors behave as short circuit

C. Capacitors behave as short circuit

D. Resistors behave as open circuits

B. Inductors behave as short circuit

An emf induced by the changing of current in the neighboring coil is called:

A. speed

B. mutually induced

C. self-induced

D. series

B. mutually induced

Find the average flux passing through a 0.5m long inductor carrying 10 Amp current if it has 100 turns and a cross sectional area of 0.1 sq.meter.

A. 251×10^-6 Wb

B. 0.1 mWb

C. 1 mWb

D. 50 mWb

A. 251×10^-6 Wb

A 2-T uniform magnetic field makes an angle of 30° with the z axis. The magnetic flux through a 3-m² portion of the x-y plane is _____ Wb.

A. 12

B. 6

C. 4.3

D. 5.2

D. 5.2

Determine the force in pounds upon each side of a coil of 40 turns carrying a current of 15 Amp if the axial length of the coil is 10 inches and the flux density is 20,000 lines per sq. inch. The conductors are at right angle to the flux.

A. 5.3 lbs

B. 10.6 lbs

C. 21.2 lbs

D. 12.4 lbs

B. 10.6 lbs

You are facing loop of wire which carries a clockwise current of 3.0 Amp and which surrounds an area of 5.8×10^-2 m². The magnetic dipole moment of the loop is ______.

A. 3.0 A-m²; away from you

B. 3.0 A-m²; towards from you

C. 0.17 A-m²; away from you

D. 0.17 A-m²; towards from you

C. 0.17 A-m²; away from you

A rectangular coil of 25 loops is suspended in a field of magnetic induction of 0.2 Tesla. The plane of the coil is parallel to the direction of the field. The dimensions of the coil are 15cm perpendicular to the field lines and 12cm parallel to them. that is the current in the coils if there is a torque of 5.4 Newton-meter acting on it.

A. 30 Amp

B. 60 Amp

C. 40 Amp

D. 50 Amp

B. 60 Amp

A magnetic circuit consists of silicon steel of 3000 permeability and an air gap. The length of the steel core is 10 cm and the air gap is 2 cm both have the same cross-section of 1.5 sq. cm. A current of ½ amp flows through the windings to produce 2351 Maxwell flux. how many turns are there in the coil?

A. 4,120 turns

B. 500 turns

C. 2,500 turns

D. 1,250 turns

B. 500 turns

Pole strength 160 and 192 are separated by a distance has a force of 19600 dynes. What is the distance in cm? integer choices

A. 1

B. 2

C. 3

D. 4

A. 1

Two parallel wires carrying equal current of 10 A attract each other with a force of 1 mN. If both currents are doubled the force of attraction will be:

A. 1 mN

B. 0.5 mN

C. 4 mN

D. 0.25 mN

C. 4 mN

A current of 2 Amp through a coil sets up flux linkages of 4 Wb-turns. What is the inductance of the coil?

A. 8 H

B. 0.5 H

C. 2H

D. 1H

C. 2H

A 3-H inductor has 2000 tums. How many turns must be added to increase the inductance to 5-7

A. 525

B. 582

C. 2582

D. 2825

C. 2582

A magnetic coil produces 100,000 maxwells with 1,000 turns and with a current of 2 Amp. The current is cut-off and the flux collapses in 0.01 sec. What is the average voltage that will appear across the coil?

A 10 V

B. 1.000 kV

C. 100 V

D. 1 kV

C. 100 V

A 50 mH inductance carries a current of 10 Amp which reverses in 5 milliseconds. What is the average voltage induced in the inductor because of this current reversal?

A. 100 Volts

B. 200 Volts

C. 400 Volts:

D. 50 Volts

A. 100 Volts

A metal transport plane has a wing spread of 88 ft. What difference of potential exists between the extremities of the wings, when the plane moves horizontally with the speed of 150 miles per hour. The value of the vertical-component of the earth's magnetic field is 065 Gauss at the plane.

A. 0.12 Volt

B. 0.24 Volt

C. 12 Volt

D. 1.2 Volts

A. 0.12 Volt

Find the value of an inductor which carries 2 Amp of steady current and in which 20 Joules of energy is stored?

А. 0.2Н

B. 5H

C. 10 H

D. 0.5 H

C. 10 H

Two identical coupled coils have an equivalent inductance of 80 mH when connected in series aiding, and 35 mH in series opposing. What is the value of coefficient of coupling k?

А. 0.931

В. 0.319

C. 0.391

D. 0.913

C. 0.391

Two coils of inductance 6 & 4 Henries are connected in parallel such that its coefficient of coupling is 41% with mutual inductance opposes the self-inductance. What is the total inductance of the combination?

A. 0.94 H

В. 3.33 Н

C. 1.43 H

D. 0.49 H

C. 1.43 H

When one coil of magnetically coupled pair has a current of 5 Amp, the resulting flux Ф₁₁ = 0.4 mWb and flux Ф₁₂ = 0.8 mWb respectively. If the turns are $N_1$ = 500 and $N_2$ = 1500, Find$L_1$, and coupling coefficient k.

A. 60 mH, 0.50

B. 80 mH, 0.60

C. 120 mH, 0.67

D. 100 mH, 0.33

C. 120 mH, 0.67

The coulomb force, F, acts on two charges a distance, r, apart. What is F proportional to?

А. г

B. r²

C. 1/r²

D. 1/г³

C. 1/r²

Which statement about a charge placed on a dielectric material is TRUE?

A. The charge is instantly carried to the material's surface

B. The charge is immediately lost to the atmosphere.

C. The charge is confined to the region in which the charge was placed.

D The charge reduces the conductivity of the material.

C. The charge is confined to the region in which the charge was placed.

 What will happen to an insulating medium with voltage more than breakdown voltage is applied?

A. it will get punctured

B. it will become magnetic

C. it will melt

D. its molecular structure will change

A. it will get punctured

Permittivity is expressed in _____

A. Farad/sq-m

B. Farad/meter

C. Weber/meter

D. dimensionless

B. Farad/meter

The inverse capacitance is called

A. Reluctance

B. Conductance

C. Susceptance

D. Elastance

D. Elastance

 For which of the following parameter variation, the capacitance of the capacitor remains unaffected?

A. Distance between plates

B. Area of the plates

C. Nature of dielectric

D. Thickness of the plates

D. Thickness of the plates

Equal amount of electrons are placed in two spheres 3 cm apart in air. If the resultant force is 4 kN how many electrons does each spheres contain?

A. 1.44 ×10¹⁴

B. 1.33 ×10¹⁴

C. 1.25 ×10¹⁴

D. 1.75×10¹⁴

C. 1.25 ×10¹⁴

Four 3 pCoul spheres are in corners of a square 1 cm on sides. Find the force in Newton?

A. 8.1 ×10^-10

B. 15.5 ×10^-10

C. 4.05 ×10^-10

D. 20.25 ×10^-10

B. 15.5 ×10^-10

Two equal charges of opposite signs are separated by a horizontal distance of 70 mm. If the resultant electric field at the midpoint of the line is 4×10⁴ N/C. Find the magnitude of each charge.

A. 3.6 nC

B. 4.5 nC

C. 2.7 nC

D. 2.4 nC

C. 2.7 nC

A condenser of 8 micro-farad capacitance is charge by connecting its plate to a 220 Volt battery. What is the charge in micro-coulomb?

A. 1760

В. 27.5

C. 1840

D. 1936

A. 1760

A plate capacitor is made up of 501 sheets of aluminum 25cm x 30cm with a dielectric of paraffin paper 0.0015 cm thick. What is the capacitance in micro-farads of the condenser (K for paraffin paper is 2.3)

A. 35

В. 25

C. 75

D. 50

D. 50

Given a charge of 36 Coul at time of 4 millisecond. Find the current.

A. 9x10^-6 A

В. 0.09 А

C. 0.9 x10^-3 A

D. 9 A

A. 9x10^-6 A

Find the value of a capacitor with 500 Volts across it, in which 20 Joule of energy is stored

A. 150 micro-farad

B. 300 micro-farad

C. 160 micro-farad

D. 320 micro-farad

C. 160 micro-farad

Three capacitors are connected in series 6, 7 and 18 micro-farad across a 100 Volt source. What is the voltage across the 7 micro-farad capacitor?

A. 15.2 Volts

B. 30.4 Volts

C. 45.6 Volts

D. 39.1 Volts

D. 39.1 Volts

A capacitor “C" is connected in parallel with a series combination of capacitors of 8 µF and 4 µF The voltage drop across capacitor "C” is 12 Volts. The 3 capacitors have been connected for sometime and have reached their present value Find the voltage across the 8 µF capacitor.

A 4 Volts

B. 9 Volts

C 5 Volts

D. 8 Volts

Which of the following can be used to measure small dc generated voltages?

A. Galvanometer

B. Thermocouple

C. Pyrometer

D. Voltmeter

For measuring the resistance of the elements of an attenuator which of the following is the best choice?

A. Maxwell's bridge

B Ohmmeter

C. Megger

D. Wheatstone bridge

A certain galvanometer has a resistance of 100 ohm and requires 1 mA for full scale deflection. To make this into a voltmeter reading of 1 full scale Connect a resistance of?

A. 1000 ohm in parallel

B. 1000 ohm in series

C. 900 ohm in series

D. 900 ohm in parallel

C. 900 ohm in series

A certain voltmeter has an internal resistance of 10 k-Ω and a range from 0 - 12 V. To extend its range to 120 V, user a series resistance of ______ Ω.

A 105,000

B. 90,000

C. 100,000

D. 120,000

B. 90,000

To roughly check his kWh meter an electrician hook-up a wattmeter, he switched on the load, he counted 5 rev in 18 sec, the meter constant is 3.2. The wattmeter reads 3368 Watts. What is the error of the meter?

A. 8% slower

B. 5% faster

C. 8% faster

D. 5% slower

D. 5% slower