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WorksheetsQUIZ-2 EM-1
Total questions: 10
Worksheet time: 5mins
The armature of DC motor is laminated to ____________
To reduce mass
To reduce hysteresis loss
To reduce eddy current loss
To reduce inductance
When Ea>Vt machine is said to be operating in which of the following mode?
Depends on the Shaft speed
Generating
Motoring
Inducing
Why starters are required in a DC motor?
Back emf of these motors is zero initially
These motors are not self-starting
These motors have high starting torque
To restrict armature current as there is no back emf at starting
In a DC shunt motor, speed is related to armature current as _____________
Directly proportional to the armature current
Inversely proportional to the armature current
Proportional to the square of the current
Independent of armature current
No-load speed of which of the following DC motor will be highest?
Series motor
Cumulative compound motor
Shunt motor
Differentiate compound motor
What will happen, with the increase in speed of a DC motor?
Back emf increase but line current falls.
Back emf falls and line current increase.
Both back emf as well as line current increase.
Both back emf as well as line current fall.
Which part will surely tell that given motor is DC motor and not an AC type?
Winding
Shaft
Commutator
Stator
Direction of rotation of motor is determined by ____________
Faraday’s law
Lenz’s law
Coulomb’s law
Fleming’s left-hand rule
The current drawn by the armature of DC motor is directly proportional to
Torque
Speed
The voltage across the terminals
Cannot be determined
In which of the following case we will get maximum power?
Ea = 2 x supply voltage
Ea = supply voltage
Supply voltage = 2 x Ea
supply voltage = 4 x Ea
