WorksheetsFundamentals Of Electric Circuit
Total questions: 138
Worksheet time: 1hrs 9mins
Which of the following appliances do NOT require electricity
Table lamp
Refrigerator
Computer
Cooking stove
Through which of the following does the electricity flow?
Pipe
Chimney
Copper wire
Tube
Which of the following is NOT an example of static electricity?
Charging of mobile phone
Lightning
Rubbing a balloon on your hair
Clothes tumbling in dryer
Which of the following is a bad conductor of electricity?
Copper wire
Wood
Salt water
Gold
Out of the following, which one is not a source of electrical energy?
Solar Cell
Battery
Potentiometer
Generator
What is the SI unit of charge?
Coulombs
Voltage
Watt
Amps
What type of current does a battery give?
Alternating current
Rotating current
Static current
Direct current
What do we mean when we say electric current is flowing?
Atoms are moving
Heat is flowing
Charge is flowing
Protons are flowing
How much of current flowing through the body can cause cardiac arrest?
5mA
10mA
20mA
50mA
Power is the rate of doing work. A bulb has a power of 200W. What is the energy dissipated by it in 5 seconds?
200J
1000J
40J
5J
Power is the rate of doing work. A bulb has a power of 200W. What is the energy dissipated by it in 5 minutes?
60kJ
200J
1kJ
10kJ
A water pump consumes 2kJ of energy in 10 seconds. What is the wattage of the motor?
2000W
20kW
10W
200W
In how many seconds will a 500W motor consume 5kJ of energy?
10 Seconds
5 seconds
500 seconds
100 seconds
What quantities do you need to calculate energy?
Current and Voltage
Resistance and current
Power and time
Power and Voltage
How many kilowatts are in 6500 W?
65kW
6.5kW
.65kW
.065kW
Voltage source and terminal voltage can be related as ___________
Terminal voltage is higher than the source emf
Terminal voltage is equal to the source emf
Terminal voltage may exceed source emf
Terminal voltage is always lower than source emf
In case of ideal current sources, they have ___________
Zero internal resistance
Low value of voltage
Large value of current
Infinite internal resistance
Ideal current source has infinite resistance. For a current source to be neglected, the terminals across the source should be ___________
Replaced by inductor
Replaced by some resistance
Open circuited
Short circuited
In case of ideal voltage sources, they have ___________
Zero internal resistance
Low value of voltage
Large value of current
Infinite internal resistance
Ideal voltage source has zero resistance. For a voltage source to be neglected, the terminals across the source should be ___________
Replaced by inductor
Replaced by some resistance
Open circuited
Short circuited
In India with what voltage do the electrical appliances work?
110 V D C
230 A C
0 - 5 V
None of these
Electrical technology does NOT deal with which one of the following?
Generation
Storage
Amplifying
Distribution
Mobile is an example of which type of device?
Electrical
Electronic
Electrical or Electronic
Information technology
Using old and new batteries together is ________.
Not good
Good
Not effects to battery
Will not work
What will happen if the battery is wrongly connected on charge?
Current delivered by the battery will be high
Current drawing will be Nil
Current drawing will be very small
Current drawing will be very high
While preparing electrolyte for a lead-acid battery ________
Water is poured into acid
Anyone of the two can be added to other chemical
Acid is poured into water
Water is not required
What electrolyte is used in lead-acid cell?
NaOH
Only H2SO4
Only water
Dilute H2SO4
Level of electrolyte in a cell should be ______ the level of plates.
Below
Equal to
Above
Does not matter
The power sources which are required to be connected in parallel, must have the ---- Voltage rating.
Same
Higher
Lower
Double
We have batteries of 2V, 200Ah. We require to 12V supply. How many batteries and how should they be connected?
6 batteries in parallel
6 batteries in series
12 batteries in series
3 in series and 3 in parallel
We have batteries of 2V, 200Ah. 6 of them are connected in series. What is the output voltage and the rating?
2V, 200Ah
12V, 1200Ah
12 V, 200Ah
2V, 1200Ah
Five 12V, 200Ah batteries are connected in parallel. What is the output voltage and the rating?
12V, 200Ah
12V, 1000Ah
50V, 200Ah
50V, 1000Ah
We have batteries of 12V, 200Ah. We require to 1000Ah capacity. How many batteries and how should they be connected?
5 batteries in parallel
5 batteries in series
10 batteries in series
2 in series and 2 in parallel
The +ve terminal of a 12V battery is connected in series to +ve terminal of 9V battery. What output voltage do we get?
21V
9V
12V
3V
The +ve terminal of a 12V battery is connected in series to -ve terminal of 9V battery. What output voltage do we get?
21V
9V
12V
3V
The capacity of a battery is expressed in terms of
Current rating
Voltage rating
Ampere hour rating
In watts
For how much time will a 1Ah battery give 1A current?
1 minute
1 sec
1 hour
10 minutes
For how much time will a 40Ah battery give 2A current?
40 hours
80 hours
2 hours
20 hours
A water pump requires 4 amps current. What minimum capacity battery must be connected to run the motor for 15 minutes?
1 Ah
15Ah
4 Ah
60Ah
A mobile has 3000mAh battery. If the mobile consumes 20mA current, then how long will the battery last?
20 hours
60 hours
50 hours
24 hours
Capacity of dry cells is ____
More when it is supplying current for intermittent periods
More when it is supplying current for continuous period
Unaffected by the type of discharge
More when it is supplying heavy current
Shelf Life of a small dry cell is
Equal to that of larger dry cell
Less than that of large dry cell
More than that of large dry cell
May be more or less
Which of the following primary cells has the highest voltage?
Manganese-alkaline
Carbon-zinc
Lithium
Mercury
The electrode for a battery must be
A semi conductor
An insulator
A good conductor of electricity
A bad conductor of electricity
Why are cells connected in series?
Increase the voltage rating
Increase the current rating
Increase the life of the cells
Increase efficiency
Five 2V cells are connected in parallel. What will be the output voltage?
1V
1.5V
1.75V
2V
Why do cells have vent cap on them?
To allow gases out when the cell is on charge
To add water to the cell if needed
To check the level of electrolyte
To check the level of electrolyte
What type of energy conversion takes place in a cell?
Chemical to electrical
Mechanical to electrical
Potential to electrical
Electrical to chemical
What type of cell gives power by an irreversible chemical reaction?
Reserve cell
Solar cell
Primary cell
Secondary cell
Battery container should be acid resistant. What material is used for making battery containers?
Glass
Plastic
Wood
All of the mentioned
What type of cell gives power by reversible chemical reaction?
Reserve cell
Solar cell
Primary cell
Secondary cell
X is used at 10% DoD, while battery Y is used at 80% DoD. Which battery will have better Cyclic life?
X
Y
Both will have same life
Can not predict
In superposition theorem, when we consider the effect of one voltage source, all the other voltage sources are ____________
Shorted
Opened
Removed
Undisturbed
In superposition theorem, when we consider the effect of one current source, all the other current sources are ____________
Shorted
Opened
Removed
Undisturbed
Superposition theorem does not work for ________
Current
Voltage
Power
Works for all: current, voltage and power
A 2k ohm is connected in series with 3k ohm. 6k ohm is connected in parallel to 3k ohm. What is the resultant of these three resistances?
11k ohm
4k ohm
5k ohm
9k ohm
A 2k ohm is connected in parallel with 1k ohm. 6k ohm is connected in parallel to 3k ohm. The two are connected in series. What is the resultant of these four resistances?
12k ohm
2.66 ohm
6.66 ohm
2.33 ohm
One terminal of 4, 8 and 2 ohm resistances are connected to form one node. The -ve terminals of 48V and 24V power sources are connected to the free end of 2ohm. The +ve terminal of 48V is connected to 4 ohm and that of 24V is connected to 8 ohm free terminals. What is current flowing through 2 ohm resistance?
6.86A
1.71A
5.15A
8.57A
One terminal of 4, 8 and 2 ohm resistances are connected to form one node. The +ve terminal of 48V is connected to 4ohm and -ve terminal to 2 ohm. A current source of 3A is connected between 2 and 8 ohms such that current is flowing in to 8 ohm. What is current flowing through 4 ohm resistance?
3A
10A
8.57A
7A
1k, 2k and 3k ohm are connected in series with a 48V power supply. What voltages appear across each of the resistances?
1V, 2V and 3V
8V, 16V and 24V
16V, 16V and 16V
10V, 20V, and 30V
3 circuit elements are connected to a node in a circuit. 2.5A current is flowing into the node through 3k Ohms. 2A current is flowing from the node towards 2.2k ohms. How much current and in what direction is the current flowing in the third element of 3.3k ohms?
2.5A into the node from the resistance
0.5A into the node from the resistance
0.5A from the node towards resistance
2.5A from the node towards resistance
4 circuit elements are connected to a node in a circuit. 1.5A current is flowing into the node through each two 3k Ohms. 4A current is flowing from the node towards 1k ohms. How much current and in what direction is the current flowing in the fourth element of 2.2k ohms?
1.5A into the node from the resistance
1A into the node from the resistance
1A from the node towards resistance
1.5A from the node towards resistance
In KVL the algebraic sum of all voltages within the loop must be equal to ----------------
V=IR
twice
unity
zero.
A 80V battery is supplying power to a 24V fan and a 36V bulb connected in series. You have to connect a motor in series. What voltage motor can be connected?
20V
24V
36V
80V
20k and 30k ohm resistances are connected in series. The +V terminal of 8V battery is connected to the free end of 20k ohm resistance. The +V terminal of 3V battery is connected to the free end of 30k ohm resistance. The -ve terminals of both batteries are shorted. If the voltage drop across 20k ohms is 2V, what is the voltage drop across 30k ohms?
3V
8V
2V
11V
A 12V battery is connected to 3k ohm resistance. What current is flowing in the cirvcuit?
4 mA
4A
.04A
.4A
A 12V battery is supplying 2A of current to a mini motor. What is the resistance of the motor?
12 ohms
8 ohms
6 ohms
4 ohms
A hair drier of 9.6 ohms requires 10A current. How much voltage does the drier require?
96V
12V
10V
9.6V
The point where the terminals of two or more circuit elements meet is called _________
branch
node
loop
tree
A ------------- is any closed path in a circuit.
branch
node
loop
tree
A 5V battery, resistances of 10k ohms and 33k ohms are connected in series. Then resistance 22k ohms is connected in parallel to 33k ohms. How many nodes does the circuit have?
2 nodes
3 nodes
4 nodes
6 nodes
A 5V battery, resistances of 10k ohms and 33k ohms are connected in series. Then resistance 22k ohms is connected in parallel to 33k ohms. How many loops does the circuit have?
2 loops
3 loops
4 loops
6 loops
A 5V battery, resistances of 2.2k ohms and 2.7k ohms are connected in series. Then resistance of 3.3k ohms is connected in parallel to 2.2k ohms. Another current source of 3A is added parallel to 3.3k ohms. How many nodes does the circuit have?
2 nodes
3 nodes
4 nodes
6 nodes
A 5V battery, resistances of 2.2k ohms and 2.7k ohms are connected in series. Then resistance of 3.3k ohms is connected in parallel to 2.2k ohms. Another current source of 3A is added parallel to 3.3k ohms. How many loops does the circuit have?
2 loops
3 loops
4 loops
6 loops
One complete variation of sine wave from zero to positive peak, back to zero, then negative peak and again back to zero is referred as:
amplitude
RMS
cycle.
period
The time taken by the waveform to complete one full cycle is called the ___________ of the waveform.
1kHz frequencty
time petriod
cycle.
duration of wave
The number of cycles per second is ___________.
frequency
time petriod
cycle.
duration of wave
Amplitude is __________ of the Signal.
Strength
Frequency
Time period
None of the these
A time taken by a signal to change from low value to high value is called ___________.
wave length
time period
fall time
rise time
A time taken by a signal to change from high to low value is called _________.
wave length
time period
fall time
rise time
One sine wave has a positive-going zero crossing at 15° and another sine wave has a positive-going zero crossing at 55°. What is the phase angle between the two waveforms?
0 degree
45 degree
40 degree
135 degrees
A sine wave of 15 kHz is changing at a faster rate than a sine wave with a frequency of __________.
1.3MHz
25kHz
18kHz
12kHz
Sine wave A has a positive-going zero crossing at 45°. Sine wave B has a positive-going zero crossing at 60°. Which of the following statements is true?
Wave A lags wave B by 15°
Wave A leads wave B by 15°
Wave A leads wave B by 105°
Wave A lags wave B by 105°
A sine wave goes through 10 cycles in 20 μs. What is the period of the wave?
2 μs
4 μs
20 μs
100 μs
The frequency of power supply in India is 50Hz. What is the time period of the waveform?
50ms
35ms
20ms
16.66ms
The frequency of power supply in India is 50Hz. Assuming that the electrons travel very close to C (the speed of light), what is the wave length of the waveform?
6000km
50km
5000km
220km
A sine wave has a frequency of 100 Hz. How many cycles will it go through in 12s?
1/100 cycle
12 cycles
120 cycles
1200 cycles
What is the frequency of a signal with a 400 μs period?
250Hz
2500Hz
25000Hz
400Hz
In AC the current and voltage change their direction with respect to _______.
current
time
voltage
Refrequency
Motors convert______________ energy into mechanical energy.
displacement
pressure
electrical
light
Which of the following appliances do not work with AC?
Washing machine
Grinding machine
Water heater
Laser pointer
AC waveform consists of ______________.
No cycles
Negative and positive half cycles
Negative cycles
increasing cycles
What type of wave is a sine wave?
continuous wave.
discrete
complex
clipping wave
A sinusoidal current has an rms value of 14 mA. What is the peak-to-peak current value?
45.12 mA
39.6 mA
16 mA
22.6 mA
The rms current through a 4.7 kΩ resistor is 4 mA. What is the peak voltage drop across the resistor?
4V
18.8V
26.6V
2.66V
The rms voltage drop across a 15 kΩ resistor is 16 V. What is the peak current through the resistor?
15mA
10mA
5mA
1.5mA
Two series resistors are connected to an ac source. There is 7.5 V rms voltage drop across one resistor and 4.2 V rms across the other. What is the peak source voltage?
16.54V
1.65V
10.60V
5.93V
What is the minimum number of wires used to connect single phase power supply?
4 wires
2 wires
3 wires
1 wire
Which of the following is true for a single phase power supply?
Only current has sine wave
Only voltage has sine wave
Current and voltage have sine wave
current and voltage are constant
What is the Power Factor of DC
1
Between 0 & 1
more than 1
less than 0
What is the Power Factor of AC
1
Between 0 & 1
more than 1
less than 0
The ratio between the active power and apparent power is called power factor. Power factor can also be defined as _________.
Cosine of angle between current and voltage of an Ac circuit
Sine of angle between current and voltage of an Ac circuit
sum of current and voltage of an Ac circuit
product of current and voltage of an Ac circuit
Low power factor has a drawback of __________.
Increased transmission and distribution losses
Poor voltage regulation
High cost of equipment for given load
All of these
The power which is actually consumed or utilized in an AC Circuit is called ----------------
True power
Reactive Power
Apparent Power
power
The product of applied voltage and active component of the current.
True power
Reactive Power
Apparent Power
power
The product of applied voltage and the reactive component of the current.
True power
Reactive Power
Apparent Power
power
The product of R.M.S value of voltage (V) and current (I).
True power
Reactive Power
Apparent Power
power
What will be the power when Current and Voltage are 90 Degree Out of Phase?
Minimum
Maximum
Infinite
zero.
What will be the power in a pure capacitive circuit?
Minimum
Maximum
Infinite
zero.
What will be the power in a pure inductive circuit?
Minimum
Maximum
Infinite
zero.
The primary reason for low power factor is owing to installation of __________
Synchronous motor
DC motor
Induction motor
Commutator motor
Medium size induction motor will operate at maximum power factor while operating at ________
Full load
50% of full load
25% of full load
Any load
Medium size induction motor will operate at lowest power factor while operating at ________
high load
low load
overload
Any load
An alternator is supplying a load of 300kW at 0.6 p.f lagging. What is the apparent power supplied by the alternator?
200kVA
180kVA
500kVA
300kVA
An alternator is supplying a load of 300kW at 0.6 p.f lagging. If the p.f. is raised to unity, then how many more kilowatts of power can the alternator supply for the same kVA loading?
200kVA
180kVA
500kVA
300kVA
In order to improve the power factor which device should be connected to the power system?
Series capacitor
Series inductor
Shunt capacitor
Shunt inductor
A motor has a rating of 169.71VA. The wattmeter shows power consumption of 119.9w. What is the PF of the motor?
1
0.76
0.9
0.71
The resistive load obstructs the flow of electrical energy in the circuit and converts it into _________ energy.
light
thermal
inductive
chemical
What type of load are the lamp and the heater?
resistive
inductive
capacitive
none of these
What is the power factor of a resistive load?
0
1
0.5
0.8
Generators are the examples of what type of load?
resistive
inductive
capacitive
none of these
In case of leading P.F, what is leading?
power
voltage
current
in phase
In case of lagging P.F, what is lagging?
power
voltage
current
in phase
Motor offers inductive load due to coils. If motor is connected as load, then what is true?
voltage lags
current lags
current leads
both are in phase
Battery offers capacitive load due to storage plates. In a battery charging plant, what is true?
voltage leads
current lags
current leads
both are in phase
The power factor of the inductive load is ____________
lagging
leading
unity
no change
The power factor of the capacitive load is _____________
lagging
leading
unity
no change
In the pure capacitive circuit, the current always _______ the voltage.
180 degree lags
180 degree leads
90 degree lags
90 degree leads
The power factor of the inductive load is lagging. How can this power factor be improved?
Static capacitors
Synchronous condenser
Phase advancer
All of these
For a consumer what is the most economical power factor?
0.25 to 0.5 lagging
0.25 to 0.5 leading
0.85 to 0.95 lagging
0.85 to 0.95 leading
What is the most suitable location of a power factor improvement device?
Near the electrical appliances which is responsible for poor power factor
At the receiving end in case of transmission line
At the sending end
Both (a) and (b)
How many wires does a three phase system consist of?
2 or 3
2 wires
3 or 4 wires
more than 5
What type of connection is used for long distance transmission?
star
delta
DC
single phase
What is the phase difference between the phases of 3-phase supply system?
0 degree
90 degrees
120 degrees
180 degrees
What is the sum of all the voltages In a three phase AC circuit?
Infinite (∞) V
0V
1 V
240V
The kilowatt-hour is the unit of _________.
electrical charge
electrical power
electrical energy
voltage
It costs Rs. 10 for 1 kWh of electrical energy. How much will it cost to run a 60 W lamp for 10 hours?
Rs. 10
Rs. 6.60
Rs. 0.6
Rs. 6
An electric rice cooker rated 800W, 230V is switched on for 30 minutes. How much electrical energy is used?
400kWh
0.4kWh
3.48kWh
104kWh
