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WorksheetsCBT Unit1
Total questions: 30
Worksheet time: 18mins
Name
Class
Date
1.
What is the relationship for stored energy in a capacitor?
a)
½ C*V ^2
b)
2 CV2
c)
½ C^2 *V
d)
2 C^2V
2.
Determine the power dissipated by a resistor having an impressed voltage of 10 Volts and a resistance of 50 ohms.
a)
2 W
b)
4 W
c)
6 W
d)
8 W
3.
What condition is needed for a circuit breaker to operate to open the circuit?
a)
No load
b)
Short circuit
c)
Normal load
d)
Open circuit
4.
A 48 Volts battery is connected to a resistance of 2.4 ohms. What is the value of the current flowing in the circuit?
a)
50 A
b)
40 A
c)
20 A
d)
15 A
5.
What is the effect of moving a single length of conductor at right angles through a magnetic field?
a)
Current is produced
b)
Heat is produced
c)
Force is produced
d)
EMF is produced
6.
What is the function of a potentiometer?
a)
To produce a magnetic field
b)
To provide variable voltages
c)
To provide a heating element
d)
To add fixed resistance into a circuit
7.
What current does a short circuit produce?
a)
Zero current
b)
Steady current
c)
Overload current
d)
Excessive current
8.
What is the unit to measure the quantity of EMF?
a)
Volt
b)
Joule
c)
Ampere
d)
Coulomb
9.
What is the effect when electrons collect on the surface of an insulating material due to friction?
a)
Current electricity
b)
Chemical charge
c)
Magnetic charge
d)
Static electricity
10.
The ammeter reads 2.5 A and the Voltmeter reads 10 V, what is the value of the resistance?
a)
2 Ω
b)
5 Ω
c)
4 Ω
d)
50 Ω
11.
How is the armature in a dc generator connected to an external circuit?
a)
Through slip rings
b)
Through a resistor
c)
Through a commutator
d)
Through a fixed contact.
12.
What type of switch is a manual single-pole single-throw (SPST) switch?
a)
One way
b)
Two way
c)
Relay
d)
Intermediate
13.
Calculate the time constant of a circuit having a resistance of 5 Mega-ohms and capacitance of 7 micro-Farad.
a)
25 seconds
b)
35 seconds
c)
45 seconds
d)
55 seconds
14.
What is the relationship between Work and Force?
a)
Force = Work x Time
b)
Force = Work ÷ Time.
c)
Work = Force ÷ Distance
d)
Work = Force x Distance
15.
What type of cells convert chemical energy from a fuel into electricity through a chemical reaction with oxygen?
a)
A fuel cell
b)
An oxygen cell
c)
A chemical cell
d)
An electric cell
16.
What is the power dissipated in a circuit carrying 2 A with an overall resistance of 100 Ω?
a)
100 W
b)
200 W
c)
400 W
d)
800 W
17.
After what period is a capacitor considered to be fully charged when connected to a battery?
a)
One second
b)
Five seconds
c)
One time constants
d)
Five time constants
18.
A voltmeter across a load reads 100 V and an ammeter indicates a load current of 2.5 A. What is the resistance of the load?
a)
25 Ω
b)
40 Ω
c)
250 Ω
d)
400 Ω
19.
Which units are used to determine electrical power in Watts?
a)
Newtons/second
b)
Joules seconds
c)
Joules/second
d)
Newton seconds
20.
What effect does an open circuit condition have on the current in a dc circuit?
a)
Current increases
b)
Current reduces
c)
Current falls to zero
d)
Current is unchanged
21.
What effect produces a force of attraction when current is passed through a relay coil?
a)
Heating
b)
Magnetic
c)
Radiation
d)
Chemical
22.
What process does a fuel cell use to produce electrical energy?
a)
Heat reaction
b)
Magnetic action
c)
Chemical reaction
d)
Photovoltaic action
23.
What happens to the resistance of a copper conductor if its temperature is increased?
a)
It stays the same
b)
It falls to zero
c)
It increases
d)
It decreases
24.
Determine the value of the energy stored in the 1 Farad capacitor with an applied voltage of 10 Volts?
a)
25 Watts
b)
30 Watts
c)
70 Watts
d)
50 Watts
25.
What process does a fuel cell use to produce electrical energy?
a)
Heat reaction
b)
Magnetic action
c)
Chemical reaction
d)
Photovoltaic action
26.
A series circuit consisting of 100 µF and a resistor of 200 Ω is connected to a DC supply. What is the time constant of the circuit?
a)
200 ms
b)
100 ms
c)
20 ms
d)
10 ms
27.
Four 1.5 V cells are connected in parallel. What is the voltage when measured at the terminals of the combination?
a)
1.5 V
b)
3.0 V
c)
6.0 V
d)
7.5 V
28.
What mechanism causes metals to corrode?
a)
Chemical reaction
b)
Magnetic reaction
c)
Photovoltaic reaction
d)
Electrostatic reaction
29.
In RC circuit, it is called the time required for a capacitor to be completely charged.
a)
Capacitor Constant
b)
Resistor Constant
c)
Electrical Constant
d)
Five Time Constant
30.
A 5 Ampere current is flowing to a resistive load with an applied voltage of 110 Volts. Determine the power delivered to the circuit?
a)
550 Watts
b)
600 Watts
c)
350 Watts
d)
100 Watts
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