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WorksheetsUnit 262 – Multiple choice practice exam
Total questions: 25
Worksheet time: 13mins
Which of the following is a unit of mass?
Newton
Newton per square metre
Kilogram
Metre
Which defines power the best
Power is proportional to the square of the time taken
Power is done when a force is moved through a distance
Power is the quality of the energy
Power is the rate of consumption of energy
Which best defines work
Work is the rate of consumption of energy
Work is the quality of energy
Work is done when a force is moved through a distance
Work is proportional to the square of the time taken
From Table 1, which of the following lists the density from low density to high density
Gold/Silver/Copper/Steel/Aluminium
Aluminium/Steel/Copper/Silver
Steel/Copper/Aluminium/Gold/Silver
Copper/Aluminium/Steel/Silver/Gold
A current of 20 A flows on a conductor of length 100mm which is at right angles to a magnetic field of flux density 0.8 T. The force exerted on the conductor would be
1.6 N
160 N
0.16 N
16 N
Which is the correct relationship between voltage, current and resistance
R=VI
V=IR
I=VR
V=RI
Which two properties affects the voltage drop along a cable
Area and type of insulation
Resistivity and density
Resistivity and length
Area and tensile strength
A disconnected cable may be live because of which of the following
Mutual Inductance
Lenz’s Law
A decrease in temperature
Increased conductivity
Energy may be stored in a cable due to
Resistance
Capacitance
Impedance
Conductivity
A magnetic field strength depends on
Distance and flux
Flux and cross sectional area
Cross sectional area and distance
Temperature and cross sectional area
The core of a transformer is laminated to reduce
Copper loss
Eddy current loss
Maintenance
Hysteresis loss
Non-electrolytic capacitors can dielectrics which include
Air, copper, iron
Paper, silver, mica
Air, polyester, polystyrene
Why must large capacitors be fitted with discharge resistors
In order to reduce buzzing
In order to prevent over heating
In order improve power factor
In order to prevent danger of electric shock
A magnetic field has lines of magnetic flux which flow from
North to South
South to North
Centre outwards
Outer to centre
Power losses on a transformer due to heating effect on windings are known as
Iron losses
Eddy current losses
Hysteresis losses
Copper losses
What describes an autotransformer?
A single windings with a tapping for the secondary
A single winding with a smaller number of turns on the secondary
Double windings with a smaller number of turns on the secondary
Double windings with a tapping on the secondary
Electric current is the flow of
E.m.f
Atoms
Electrons
Protons
A 10 Ω resistor is connected across 50 V supply. If a multi-meter records 1000Ω resistance is then correctly connected to the circuit the total current will be
Reduced to 0.25 mA
Reduced to 5 mA
Increased by 2.5mA
Increased by 50 mA
The issues effecting if a cable exceeds the voltage for a long time.
Cools and resistance increase
Overheats and the resistance reduces
Cools and insulation breakdown
Overheats and the insulation breakdown
The mechanism shown in the figure above is of
A simple toggle switch
A snap action toggle switch
An eccentric cam switch
A rocker switch
Which of the following types of spring would be most suitable for delivering a high force with a very small deflection.
Spiral
Tension
Compression
Torsion
For a beam to be in equilibrium, which one of the following conditions must exist
Forces on both sides of the pivot must be equal
Distance to load on both sides of the pivot must be equal
Turning moments on both sides of the pivot must be equal
Masses on both sides of the pivot must be equal
When a changing current in one circuit induces an e.m.f in another separate circuit, then the two circuits have
Inductive capacitance
Mutual capacitance
Mutual inductance
Capacitive inductance
Magnetic shielding of electrical plant and apparatus is required to
Reduce heating losses
Increase heating losses
Reduce interference
Increase interference
The graph above shows a materials temperature coefficient of the resistance is
Positive
Negative
Constant
irregular
