April

OBJECTIVES:

1. To know the safety Rules,

2. To know the shock treatment procedure in a practical situation.

SAFETY RULES:

1. The Golden Rule: Treat every electric wire or electrical appliance as live.

2. Before touching any wire or any electrical equipment make sure that there is no electricity.

3. Test the presence of electricity with the help of the line tester.

4. Do not touch electrical appliance with wet hands.

5. To not disconnect plug point by pulling flexible chord.

6. Do not insert wires one the plug without plug top.

RELATED INFORMATION - SHOCK TREATMENT: ​

Electrical supply is widely used in our daily life. AC supply is operated at 230 Volts and most of the domestic appliances work at this voltage. Some times due to sheer negligence (or unknowingly) we my come in contact with electricity. In such a case one will be subjected to shock and this shock could be dangerous. One should not play with electricity and should be cautious while working on electrical appliances.Some time due to loose connections, short circuits and faulty connections one may receive electric shock. We should know to treat the shock victim with first aid till medical assistance is available. When a person receives electric shock he may fall and become unconscious. In such cases

1. We must break the contact between the person and the supply.

2. We should touch the victim or try to push him with bare hands, The victim may be pushed by using a dry wooden stick. Rubber glovses if available could be used.

3. Switch off the mains.

4. Inspect the victim, give him some warm drink like coffee/tee. Make him free comfortable.

5. If the victim has breathing difficulty after the shock, give artificial respiration.

August

Objectives:

1. To acquire the knowledge on ‘Fuse’.

2. To observe the fuse wire.

3. To know how to affix a fuse.

Related Information:

The fuse is a safety device. It protects the circuit from over-load. When current exceeds the maximum limit, the fuse melts and breaks the circuit and current ceases to flow.

The fuse also blows out in the case of a short-circuit (S.C.) are dangerous. If these conditions prevail the wiring gets heated up and there is a chance of fire.

The fuse is always provided before the switch and is placed in the live wire.

Tools, Equipment and Materials required:

Materials:

1. Base board.

2. 3-Pin Top

3. Connecting wires - Red, Blue/Black - 2mtrs each.

4. Fuse carrier cum base (Kit Kat) 5 Amps – One.

5. Switch - 1no.s

6. Bulb holder (Acts as load)

7. Bulb - Bed light any bright colour.

Tools:

1. Insulated Combination Plaiers (15cm) – One.

2. Cutter(15cm)- One.

3. Screw driver (10 cm) – One.

4. Neon tester – One.

RELATED INFORMATION:

A fuse is a protective device. It is placed on a live wire before the switch as shown in Figure. Fuse protects circuits from over loading. It burns out and acts as a safety device.

A fuse -5 Amps is generally employed for lighting load. After selecting the fuse the required length of fuse wire is cut. It will be generally 8 to 10 cm.s long for 5 amps. The desired length may be measured by actual measurement of the fuse holder. Take the fuse wire and fix one end on the fuse holder(top). Now, pass the wire through the passage, screw up the other end of the fuse wire by giving a few turns in clock wise direction. Cut extra length of the fuse wire.

​Applications:

All electrical circuits are protected by fuse. Fuses are rated according to their current carrying capacity. There are many types of fuses. The fuses that are used in House-hold wiring are re-wireable type. Whenever the fuse blows out the fault must be found. Ignoring this may result in blowing out the fuse again and again. The fuse blows on account of:

1. Over loading.

2. Short-circuit.

3. Ageing.

September

Objectives:

1. To understand the connection of simple connection of a switch board.

2. To know why the live wire to be connected to switch.

Materials Required:

1. Switch board.

2. 5pin Socket.

3. 3 Pin top.

4. Straight holder.

5. SP Switches - 2 no.s

6. Connecting wires.

Related Information:

About Circuit: A single pole (S.P.) switch is used to control a lamp. another to control 3pin socket. The function of both switches for the lamp and the socket is to put the circuit 'ON' and 'OFF'.

Always live is connected through the switch, because load wire will not have any supply while switch is off.

Circuit Diagram:

Precautions:

1. All the connections should be tighten properly, there should not be any loose connections.

2. Live connections should not be exposed out. Fix the assembled hylam sheet to the board immediately.

3. Check the circuit before connecting it to the mains supply.

October

Objectives:

1. To Identify various types of Resistors.

2. To Study various measuring Instruments

Materials Required:

A: Resistors:

1. Carbon Resistor (Fixed)

2. Carbon Resistor (Variable)

3. Wire wound Resistor (Tapped)

B: Instruments:

1. Multimeter.

2. Volt meter.

3. Ammeter.

Related Information:

RESISTORS: Resistors are the electrical/electronic device, which is used to control the flow of current. It is measured in 'Ohms".

In daily life, we observe a variable resistor in fan regulator is used to control the speed of fan.

INSTRUMENTS: The Instruments are the devices, which is used to measure the physical quantity. Here we are dealing with electrical instruments, these instruments will measure electrical current, potential difference and resistance (basic physical quantities)

Current is measured in Ampere.

Potential Difference -measured in Volts.

Resistance is measured in Ohms.

November

Aim: To learn how make series and parallel circuits with LEDs.

Materials Required:

1. Base Board - 2 No.s (A5 Size)

2. Light Emitting Diodes - 6 no.s

3. Cell holder (2 Cells).

4. Cell (2 no.s AA size).

5. 9V Snap.

6. 9V battery.

7. Connecting Wires.

8. Switches - 2 no.s

Related Information:

​When a source (here electrical source is battery) is connected to various loads (here LEDs) the voltage of the sources will be shared by all three loads(3 LEDs). In the series circuit here, 9 Volts battery sources will be shared by three LED with each 3 Volts. The same current flows through all the LEDs. In parallel circuit, 3 Volt battery is connected to all three LEDs, the LEDs gets 3 Volt supply, whereas current flow from the battery will be divided to 3 LEDs.

Procedure:

1. Take two base boards, mark the items to be mounted on the base board, one for series connections, and other for parallel connections.

2. Mount the components for series connections.

3. Make the connections as per the series connections circuit.

4. Connect the 9 V snap to the 9V battery, Put ON and observe the LEDs.

5. Mount the components for parallel connections.

6. Make the connections as per the parallel connections circuit.

7. Place the pencil cells in the cell holder and put ON the switch and observe the LEDs

December

AIM: To know how does electrons flow in the conductive wire.

RELATED INFORMATION:

We know that an atom has electrons, protons and neutron. The charge of electron is negative, proton is positive and neutron is neutral. An atom is neutral as the number of electrons and protons in it are equal.

When electrical supply is given to a circuit, an atom will lose a valance electron when "pushed" by an electron from another atom till positive side of electrical supply. Flow of electrons takes place as electron collides and transfer from atom to atom. Refere the link below:

https://youtu.be/tTOwGj1d7Yw

Conventional current:

A flow of current in a wire is flow of negatively charged electrons. That is, the negative terminal to the positive in an electric circuit. In electrical engineering we always use conventional current which is the direction of positively charged particles, it is from positive terminal to negative terminal.

January

AIM:

1. To learn the definitions of Work, Power and Energy.

2. To know about electrical energy being consumed at home and in school.

Related Information:

WORK: When a force acts upon an object to cause a displacement of the object, it is said that work was done upon the object.

POWER: The work is done very quickly and other times the work is done rather slowly. Power is the rate at which work is done. It is the work/time ratio.

ENERGY: Power consumption per hour - Units: Watt-hour.

February

Electricity sources are:

1. Hydal

2. Solar

3. Wind

4. Sun.

5. Nuclear

March

Magnet is Naturally formed.

Electromagnet is the magnet, which works as long as electrical power is given to a coil.