Worksheet Solutions: Electricity Projects - 2 | DIY Science Fun: Cool School Projects - Class 6 PDF Download

Fill in the Blanks

Q1: DC motors can generate electricity when their __________ are set in motion.
Ans: shafts
DC motors can generate electricity when their shafts are set in motion, altering their polarity and enabling rotation in either direction, which generates electricity.

Q2: Increasing the rotation speed of the motor's shaft can __________ the voltage produced.
Ans: augment
Increasing the rotation speed of the motor's shaft can augment (increase) the voltage produced.

Q3: The components needed for the electric generator project include DC motors, power source, small white switch, LED, resistor, and __________.
Ans: jumper wires
The components needed for the electric generator project include DC motors, power source, small white switch, LED, resistor, and jumper wires for circuit connections.

Q4: __________ is an essential electrical device that allows or interrupts the flow of electricity in a circuit.
Ans: Switch
A switch is an essential electrical device that allows or interrupts the flow of electricity in a circuit.

Q5: __________ is converted into mechanical energy in a DC motor.
Ans: Electricity
In a DC motor, electrical energy is converted into mechanical energy as the motor's shaft rotates.

Multiple Choice Questions

Q1: Which type of energy is generated by DC motors?
(a) Mechanical energy
(b) Thermal energy
(c) Chemical energy
(d) Nuclear energy
Ans: (a) Mechanical energy
DC motors generate mechanical energy.

Q2: What purpose does the resistor serve in the LED circuit of the electric generator project?
(a) To increase voltage
(b) To protect the LED
(c) To decrease current
(d) To increase brightness
Ans: (b) To protect the LED
The resistor is used to protect the LED from excessive current in the LED circuit.

Q3: In the electric generator project, what connects the shafts of the two DC motors?
(a) Switch
(b) Jumper wires
(c) Pulley
(d) LED
Ans: (c) Pulley
A pulley is used to connect the shafts of the two DC motors.

Q4: The flow of electricity in an electric circuit can be controlled using a __________.
(a) Resistor
(b) Diode
(c) Transistor
(d) Switch
Ans: (d) Switch
A switch controls the flow of electricity in an electric circuit.

Q5: What is the function of a DC motor in an electric generator project?
(a) To produce light
(b) To generate electricity
(c) To provide mechanical power
(d) To regulate current flow
Ans: (b)
To generate electricity
In the electric generator project, the DC motors are used to generate electricity.

True and False

Q1: True/False: DC motors can convert electrical energy into mechanical energy.
Ans: True
DC motors can convert electrical energy into mechanical energy.

Q2: True/False: The rotation speed of a DC motor's shaft has no effect on the voltage generated.
Ans: False
The rotation speed of a DC motor's shaft affects the voltage generated. Increasing the rotation speed increases the voltage produced.

Q3: True/False: A resistor is used to protect the LED from excessive current in the electric generator project.
Ans: True
A resistor is used to protect the LED from excessive current, ensuring the LED operates within a safe range.

Q4: True/False: The LED holder in the project can be made from an old torchlight's LED holder.
Ans: True
The LED holder in the project can be made from an old torchlight's LED holder, providing a suitable structure for the LED.

Q5: True/False: Electric circuits are essential for understanding the applications of DC motors.
Ans: True
Understanding electric circuits is essential for comprehending the applications of DC motors and related projects.

Short Answer Questions

Q1: Describe how a DC motor can generate electricity when its shaft is rotated.
Ans: When a DC motor's shaft is rotated, it causes a change in the magnetic field, inducing an electric current according to Faraday's law of electromagnetic induction. This induced current allows the DC motor to generate electricity.

Q2: Explain the role of a switch in an electric circuit.
Ans: A switch is an electrical device that allows or interrupts the flow of electricity in a circuit. When the switch is closed (on), it completes the circuit and allows electricity to flow. When the switch is open (off), it interrupts the flow of electricity.

Q3: What are the key components needed to construct an electric generator using DC motors?
Ans: The key components needed to construct an electric generator using DC motors include DC motors, power source (adapter or batteries), small white switch, LED, resistor, connector (pulley or alternative), cardboard, and additional materials like jumper wires and tools for assembly.

Q4: How does a resistor protect the LED in the electric generator project?
Ans: The resistor in the LED circuit of the electric generator project is used to protect the LED from excessive current. It acts as a barrier, limiting the current that flows through the LED, thus preventing it from being damaged due to too much current.

Q5: Mention two safety precautions to consider while working on a science project involving DC motors.
Ans: Two safety precautions when working on a science project involving DC motors:

• Wear safety glasses: Safety glasses should be worn to protect the eyes from any potential hazards during cutting, soldering, or assembling processes.
• Work under supervision: Always work under the supervision of parents, teachers, or older siblings to ensure safe and proper handling of tools and equipment, especially when using a soldering iron.