Solutions for Chapter 4: Effects of Electric Current Class 10th Solutions
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Tell the odd one out and give a proper explanation.
Odd one out: Generator
Explanation:
- Fuse wire, bad conductor, and rubber gloves are all related to electrical safety and insulation.
- A fuse wire is used to protect electrical circuits from overloading by melting and breaking the circuit.
- A bad conductor does not allow electricity to pass through easily, making it useful for insulation.
- Rubber gloves are insulating materials used to protect individuals from electric shocks.
- However, a generator is a device that produces electricity, making it different from the others, which are primarily used for electrical safety and insulation.
Tell the odd one out and give a proper explanation.
Odd one out: Thermometer
Explanation:
- The voltmeter, ammeter, and galvanometer are electrical measuring instruments used to measure voltage, current, and small electric currents, respectively.
- However, a thermometer is used to measure temperature and is not related to electrical measurements.
Tell the odd one out and give a proper explanation.
Odd one out: Magnet
Explanation:
- A loudspeaker, microphone, and electric motor all work based on the principles of electromagnetism and electrical energy conversion.
- A magnet, on the other hand, is a naturally occurring or artificially created object that produces a magnetic field but does not directly convert electrical energy into mechanical or sound energy.
Explain the construction and working of the following. Draw a neat diagram and label it.
Electric Motor
Scientific and Exam Answer
1. Introduction
An electric motor is a device that converts electrical energy into mechanical energy. It operates based on the principle of electromagnetic induction, where a current-carrying conductor experiences a force inside a magnetic field.
2. Construction of an Electric Motor
The key components of a DC Electric Motor are:
- Magnetic Field (N and S Poles): Permanent magnets or electromagnets create a uniform magnetic field inside which the coil rotates.
- Armature Coil (ABCD): A rectangular loop of insulated copper wire that rotates within the magnetic field.
- Axle: The rotating shaft connected to the coil, transmitting mechanical energy.
- Battery: The power source that provides direct current (DC) to the coil.
- Split Rings (X and Y): Also known as the commutator, they are divided into two halves and connected to the coil.
- Carbon Brushes (E and F): Graphite contacts that ensure continuous current flow into the rotating coil.
3. Diagram of an Electric Motor
4. Working of an Electric Motor
The DC motor works based on Fleming’s Left-Hand Rule, which states:
"If the thumb, forefinger, and middle finger of the left hand are stretched mutually perpendicular, then:
- Forefinger: Represents Magnetic Field (B).
- Middle Finger: Represents Current (I).
- Thumb: Represents Force (F), the direction of motion.
Step-by-step working:
- When the battery supplies current, it flows through carbon brushes into the split rings.
- The current enters the coil (ABCD) and interacts with the magnetic field (N and S poles).
- According to Fleming’s Left-Hand Rule, the left side of the coil (AB) experiences an upward force, while the right side (CD) experiences a downward force.
- This results in rotational movement in the clockwise direction.
- As the coil completes 180° rotation, the split rings reverse the current direction, ensuring continuous rotation.
5. Formula
The force on a current-carrying conductor in a magnetic field is given by:
$$ F = BIL \sin\theta $$
Where:
- F = Force on the conductor (Newton)
- B = Magnetic field strength (Tesla)
- I = Current (Ampere)
- L = Length of the conductor (Meter)
- θ = Angle between current direction and magnetic field
6. Applications of an Electric Motor
- Used in household appliances such as fans, mixers, and washing machines.
- Used in electric vehicles and industrial machines.
- Utilized in pumps, compressors, and robots.
7. Summary
- An Electric Motor converts electrical energy into mechanical energy.
- It operates based on Fleming’s Left-Hand Rule.
- The commutator ensures continuous rotation.
- It is widely used in home appliances and industries.
Explain the construction and working of the following. Draw a neat diagram and label it.
Scientific and Written Exam Answer:
Introduction:
An AC Generator (Alternator) is a device that converts mechanical energy into electrical energy in the form of alternating current (AC). It works based on Faraday’s Law of Electromagnetic Induction.
Construction of an AC Generator:
The AC generator consists of the following key components:
- Field Magnet: Provides a uniform magnetic field using permanent magnets or electromagnets.
- Armature Coil: A rectangular coil (ABCD) made of conducting wire that rotates in the magnetic field.
- Axle: The shaft connected to the coil that rotates, supplying mechanical energy.
- Slip Rings (R₁ & R₂): Two separate conducting rings attached to coil ends, ensuring continuous rotation.
- Carbon Brushes (B₁ & B₂): Maintain electrical contact with slip rings while allowing rotation.
- External Circuit: The generated current is supplied to an external circuit through the brushes.
Working Principle of an AC Generator:
The generator works based on Faraday’s Law of Electromagnetic Induction, which states that a change in magnetic flux induces an electromotive force (EMF) in a conductor.
- The armature coil rotates in the magnetic field, changing the magnetic flux linked with it.
- According to Faraday’s Law, an induced current is generated in the coil.
- The direction of the induced current is determined by Fleming’s Right-Hand Rule.
- Since the coil continuously rotates, the induced current periodically changes direction, producing **alternating current (AC)**.
- The current flows through the slip rings and carbon brushes to the external circuit, where it is utilized.
Mathematical Expression:
The induced EMF (electromotive force) is given by:
$$ e = -N \frac{d\Phi}{dt} $$where:
- e = Induced EMF (volts)
- N = Number of turns in the coil
- dΦ = Change in magnetic flux
- dt = Time interval
Conclusion:
The AC generator is widely used in power stations, hydroelectric plants, and wind turbines to generate electricity.
Example:
Wind turbines work on the same principle. When wind turns the blades, a generator inside produces electricity.
Electromagnetic induction means ______.
- Charging of an electric conductor.
- Production of a magnetic field due to a current flowing through a coil.
- Generation of a current in a coil due to relative motion between the coil and the magnet.
- Motion of the coil around the axle in an electric motor.
Scientific and Written Exam Answer:
Correct Answer: Generation of a current in a coil due to relative motion between the coil and the magnet.
Definition:
Electromagnetic induction is the process by which an electric current is generated in a conductor due to the relative motion between the conductor and a magnetic field.
Faraday's Law of Electromagnetic Induction:
According to **Faraday’s Law**, the induced electromotive force (EMF) in a coil is given by:
$$ e = -N \frac{d\Phi}{dt} $$where:
- e = Induced EMF (volts)
- N = Number of turns in the coil
- dΦ = Change in magnetic flux
- dt = Time interval
Explain the difference: AC generator and DC generator.
Scientific and Written Exam Answer:
An electric generator is a device that converts mechanical energy into electrical energy. There are two types of generators: AC (Alternating Current) generator and DC (Direct Current) generator. The key differences between them are as follows:
| AC Generator | DC Generator |
|---|---|
| Produces alternating current (AC). | Produces direct current (DC). |
| Uses slip rings for current collection. | Uses a commutator to convert AC into DC. |
| The direction of current reverses periodically. | The direction of current remains constant. |
| Can be used for power stations and industrial applications. | Commonly used in battery charging and small-scale applications. |
| Efficiency is generally higher. | Efficiency is lower compared to AC generators. |
| Maintenance is easier due to simple design. | Requires frequent maintenance due to commutator and brushes. |
| Power transmission over long distances is efficient. | Not suitable for long-distance power transmission. |
| Examples: Power plants, wind turbines. | Examples: Car alternators, battery charging systems. |
| Voltage can be easily stepped up or down using transformers. | Voltage regulation is difficult and requires additional components. |
| Generated power is used in homes, offices, and industries. | Used in specific applications like electric vehicles and electronic circuits. |
Simple and Understandable Answer:
A generator is a machine that makes electricity. There are two types:
- AC Generator: It produces electricity that changes direction continuously, just like what we use at home.
- DC Generator: It produces electricity that flows in one direction, like a battery.
Example: The electricity in our houses comes from AC generators, while a battery in a torch works on DC.
Which device is used to produce electricity? Describe with a neat diagram.
Scientific and Written Exam Answer:
The correct answer is: Electric Generator (DC).
An Electric Generator is a device that converts mechanical energy into electrical energy using the principle of electromagnetic induction. It works by rotating a coil in a magnetic field, which induces an electric current in the coil.
Working Principle:
When the coil inside the generator rotates between the magnetic poles, a changing magnetic flux is created, inducing an electromotive force (EMF) in the coil as per Faraday’s Law of Electromagnetic Induction.
Key Components of a DC Generator:
- Armature Coil: Rotates inside the magnetic field.
- Field Magnets: Provide a steady magnetic field.
- Commutator: Converts AC into DC.
- Brushes: Help in transferring current to the external circuit.
Diagram of a DC Generator:
Formula Used:
According to Faraday's Law, the induced EMF is given by:
$$ E = -N \frac{d\Phi}{dt} $$
Simple and Understandable Answer:
An Electric Generator is a machine that makes electricity when we rotate its handle or use another source of mechanical energy.
Example: The dynamo in a bicycle works as a small generator to light up the bulb.
How It Works: When the generator spins, it creates a magnetic force that produces electricity, which can be used to power different devices.
How does the short circuit form? What is its effect?
Scientific and Written Exam Answer:
A short circuit occurs when an unintended low-resistance path is created between two points in an electrical circuit, allowing a large current to flow through it.
Causes of Short Circuit:
- Direct contact between live and neutral wires.
- Damaged insulation of wires.
- Faulty electrical appliances.
- Overheating of circuits.
Effects of Short Circuit:
- Excessive current flow leading to overheating.
- Damage to electrical appliances.
- Fire hazards due to high temperatures.
- Potential electric shocks to users.
Formula Used:
The short-circuit current (I) can be calculated using Ohm’s Law:
$$ I = \frac{V}{R} $$
where:
- I = Current (A)
- V = Voltage (V)
- R = Resistance (Ω) (very low in short circuits)
Simple and Understandable Answer:
A short circuit happens when electricity flows in the wrong way, usually because two wires touch each other directly.
Example: If a wire inside a charger gets damaged and touches another wire, it can cause a short circuit.
Effects of a Short Circuit:
- It can cause sparks or fire.
- Electrical appliances may stop working.
- Too much electricity can flow and damage circuits.
To prevent short circuits, always use good-quality wiring and avoid overloading sockets.
Give a scientific reason: Tungsten metal is used to make a solenoid-type coil in an electric bulb.
Scientific and Written Exam Answer:
Tungsten is used in electric bulb filaments because of the following properties:
- High Melting Point: Tungsten has a very high melting point of about 3422°C, which prevents it from melting at high temperatures.
- High Resistivity: It offers significant resistance to electric current, allowing it to glow and emit light efficiently.
- Low Evaporation Rate: Tungsten does not evaporate quickly, increasing the lifespan of the filament.
- Good Mechanical Strength: It can withstand repeated heating and cooling cycles without breaking.
Formula Related to Resistance:
The resistance of a material is given by:
$$ R = \rho \frac{L}{A} $$
where:
- R = Resistance (Ω)
- ρ = Resistivity of tungsten (Ω·m)
- L = Length of the filament (m)
- A = Cross-sectional area (m²)
Simple and Understandable Answer:
Tungsten is used in electric bulbs because it does not melt easily and can glow brightly for a long time without burning out.
Example: If we used iron or copper instead of tungsten, the filament would melt quickly due to the high temperature.
Give a scientific reason: In the electric equipment producing heat (e.g. iron, electric heater, boiler, toaster), an alloy such as Nichrome is used, not pure metals.
Scientific and Written Exam Answer:
Nichrome, an alloy of nickel and chromium, is used in heating appliances due to the following properties:
- High Resistivity: Nichrome has higher resistivity than pure metals, allowing it to generate more heat when electric current passes through it.
- High Melting Point: It does not melt easily at high temperatures, making it durable for heating applications.
- Oxidation Resistance: Unlike pure metals like iron, Nichrome does not rust or oxidize quickly, increasing the lifespan of the device.
- Uniform Heating: It distributes heat evenly, which is essential for devices like irons and toasters.
Formula Related to Heat Generation:
The heat produced is given by Joule’s Law:
$$ H = I^2 R t $$
where:
- H = Heat energy (Joules)
- I = Current (A)
- R = Resistance (Ω)
- t = Time (s)
Simple and Understandable Answer:
Nichrome is used in heating devices because it heats up quickly without melting and does not rust.
Example: If we used copper or iron, they would melt or get damaged quickly due to high temperatures.
Give a scientific reason: For electric power transmission, copper or aluminium wire is used.
Scientific and Written Exam Answer:
Copper and Aluminium are used for electric power transmission due to the following reasons:
- Low Resistivity: Both metals have very low electrical resistivity, reducing energy loss in the form of heat.
- High Conductivity: Copper has high electrical conductivity, allowing efficient power transmission with minimal loss.
- Lightweight: Aluminium is lighter than copper, making it easier to install in long-distance transmission lines.
- Cost-effective: Aluminium is cheaper than copper, making it a preferred choice for power transmission.
- Durability: Both metals have good corrosion resistance, ensuring long-term reliability.
Formula Related to Power Loss:
Power loss due to resistance is given by:
$$ P = I^2 R $$
where:
- P = Power loss (W)
- I = Current (A)
- R = Resistance of the wire (Ω)
Simple and Understandable Answer:
Copper and aluminium are used in power transmission because they allow electricity to pass with minimal energy loss and do not overheat easily.
Example: If we used iron wires, they would heat up quickly, wasting electricity and causing damage.
Give a scientific reason: In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.
Scientific and Written Exam Answer:
kWh (Kilowatt-hour) is used instead of joules for measuring electrical energy due to the following reasons:
- Large Values: Electrical energy consumption in households and industries is very large, and joules would result in extremely high numbers.
- Practical Convenience: 1 kWh = 3.6 × 10⁶ joules, making it a more convenient unit for billing and usage tracking.
- Ease of Calculation: Power companies can easily measure and charge customers based on kWh.
- Common Usage: Electricity meters are designed to measure consumption in kWh, simplifying usage comparison.
Formula Related to Energy Consumption:
Electrical energy is calculated as:
$$ E = P \times t $$
where:
- E = Energy (kWh or Joules)
- P = Power (kW or W)
- t = Time (hours or seconds)
Simple and Understandable Answer:
kWh is used instead of joules because it is a smaller and more practical unit for measuring electricity usage.
Example: A 100 W bulb running for 10 hours consumes 1 kWh of energy, which is easier to understand than 3.6 million joules.
Which of the statements given below correctly describes the magnetic field near a long, straight current-carrying conductor?
Options:
- The magnetic lines of force are in a plane, perpendicular to the conductor in the form of straight lines.
- The magnetic lines of force are parallel to the conductor on all sides of the conductor.
- The magnetic lines of force are perpendicular to the conductor going radially outward.
- The magnetic lines of force are in concentric circles with the wire as the center, in a plane perpendicular to the conductor.
Correct Answer:
Option D: The magnetic lines of force are in concentric circles with the wire as the center, in a plane perpendicular to the conductor.
Explanation:
When a current flows through a long, straight conductor, it generates a magnetic field around it. According to the Right-Hand Thumb Rule, the magnetic field lines form concentric circles centered on the wire. The direction of these field lines depends on the direction of the current.
This pattern can be visualized using iron filings around a current-carrying wire, confirming that the field is circular.
What is a solenoid? Compare the magnetic field produced by a solenoid with the magnetic field of a bar magnet. Draw neat figures and name various components.
Scientific and Exam Answer:
A solenoid is a cylindrical coil of insulated wire wound closely in the shape of a helix. When an electric current passes through it, it produces a magnetic field similar to that of a bar magnet.
Magnetic Field of a Solenoid vs. Bar Magnet:
| Solenoid | Bar Magnet |
|---|---|
| Produces a uniform magnetic field inside the coil. | Magnetic field is strongest at the poles and weak in the middle. |
| Field lines resemble that of a bar magnet. | Has natural magnetic properties due to atomic alignment. |
| Strength can be increased by increasing current or adding an iron core. | Magnetic strength is fixed and cannot be easily changed. |
| Can be turned on or off (Electromagnet). | Permanently magnetized. |
Formula:
The magnetic field inside a solenoid is given by:
$$ B = \mu_0 n I $$
Where:
- B = Magnetic field (Tesla)
- \(\mu_0\) = Permeability of free space (\(4\pi \times 10^{-7} Tm/A\))
- n = Number of turns per unit length
- I = Current flowing through the solenoid (Ampere)
Diagram:
Simple and Understandable Answer:
A solenoid is a coil of wire that creates a magnetic field when electricity flows through it. It acts like a bar magnet, with a North and South Pole.
Comparison with a Bar Magnet:
- Just like a bar magnet, a solenoid has a magnetic field around it.
- The inside of the solenoid has a strong, uniform magnetic field.
- Unlike a bar magnet, a solenoid's magnetic strength can be controlled by adjusting the current.
- When the current stops, the magnetic field disappears.
Example:
A solenoid is used in electric door locks, relays, and MRI machines.
Name the following diagram and explain the concept behind them.
Scientific and Written Exam Answer:
The given diagrams illustrate Fleming’s Right-Hand Rule. It is used to determine the direction of the induced current in a conductor moving perpendicular to a magnetic field.
Fleming’s Right-Hand Rule: According to this rule, if the thumb, forefinger, and middle finger of the right hand are stretched mutually perpendicular to each other:
- Thumb: Represents the direction of motion of the conductor.
- Forefinger: Represents the direction of the magnetic field.
- Middle Finger: Represents the direction of the induced current.
Mathematically, the induced electromotive force (EMF) is given by:
$$ E = B \cdot v \cdot l $$where:
- E = Induced EMF (in volts)
- B = Magnetic field strength (in Tesla)
- v = Velocity of the conductor (in m/s)
- l = Length of the conductor (in meters)
This rule is applied in electric generators to determine the direction of the induced current.
Simple and Understandable Answer:
The diagrams show Fleming’s Right-Hand Rule, which helps in finding the direction of current when a conductor moves in a magnetic field.
In this rule:
- The thumb shows the direction in which the conductor moves.
- The forefinger shows the direction of the magnetic field.
- The middle finger shows the direction of the induced current.
This rule is mainly used in power generation, like in hydroelectric and thermal power plants.
Diagram:
Name the following diagram and explain the concept behind it.
Scientific and Written Exam Answer:
The given diagram represents Fleming’s Left-Hand Rule. This rule is used to determine the direction of the force acting on a current-carrying conductor placed in a magnetic field.
Fleming’s Left-Hand Rule: If the thumb, index finger, and middle finger of the left hand are stretched mutually perpendicular to each other:
- Thumb → Represents the direction of force (motion) on the conductor.
- Index Finger → Represents the direction of the magnetic field.
- Middle Finger → Represents the direction of the current.
Mathematical Expression:
Magnetic force acting on the conductor is given by:
$$ F = B \cdot I \cdot L $$
where:
- F = Magnetic force (in Newtons)
- B = Magnetic field strength (in Tesla)
- I = Current (in Amperes)
- L = Length of the conductor (in meters)
Applications:
- Used in electric motors to determine the direction of movement.
- Used in electromagnetic relays and loudspeakers.
Simple and Understandable Answer:
Fleming’s Left-Hand Rule helps to find out in which direction an electric motor moves.
How to use it:
- Stretch out your left hand.
- Keep your thumb, index finger, and middle finger at right angles to each other.
- Your index finger shows the magnetic field, your middle finger shows the current, and your thumb shows the direction of motion.
Example: If you pass electricity through a wire placed in a magnetic field, the wire will move in a direction that follows this rule. This is why electric fans and motorized toys work!
Identify the figure and give its use.
Scientific and Written Exam Answer:
The given figure represents a Cartridge-Type Fuse. It is a safety device used in electrical circuits to protect against overcurrent and short circuits.
Function:
- The fuse contains a thin wire or metal strip that melts when excessive current flows through it.
- By melting, the fuse breaks the circuit, preventing damage to electrical appliances and reducing fire hazards.
Types of Cartridge Fuses:
- Fast-blow fuse: Melts quickly in case of overcurrent.
- Slow-blow fuse: Withstands short spikes of high current before melting.
Common Applications:
- Used in electrical appliances like microwaves, televisions, and power adapters.
- Protects car circuits, industrial machines, and home wiring.
Simple and Understandable Answer:
This is a fuse, a small but important device in electrical circuits.
What does it do?
- It stops too much electricity from flowing and damaging devices.
- If the current is too high, the fuse wire inside melts and breaks the circuit.
Where is it used?
- In home appliances like TVs and refrigerators.
- In cars to prevent electrical failures.
Identify the figure and give its use.
Scientific and Written Exam Answer:
The given figure represents a Miniature Circuit Breaker (MCB). It is an automatically operated electrical switch designed to protect circuits from overcurrent and short circuits.
Function:
- The MCB trips (turns off) when excessive current flows, preventing damage to electrical appliances and wiring.
- Unlike fuses, MCBs can be reset manually after tripping.
Types of MCBs:
- Single-pole MCB: Used for single-phase circuits.
- Double-pole MCB: Used for both phase and neutral protection.
- Triple-pole MCB: Used for three-phase circuits.
Common Applications:
- Used in homes, offices, and industries to protect electrical wiring.
- Prevents fire hazards caused by short circuits or overloads.
Simple and Understandable Answer:
This is an MCB (Miniature Circuit Breaker), a safety device in electrical systems.
What does it do?
- It protects electrical circuits from too much current.
- If there is a short circuit or overload, the MCB switches off automatically.
Where is it used?
- In homes to protect wiring from electrical faults.
- In industries and offices to prevent fire hazards.
Identify the figure and explain its use.
Scientific and Written Exam Answer:
The given figure represents a DC Generator. A DC generator is an electrical machine that converts mechanical energy into direct current (DC) electricity using the principle of electromagnetic induction.
Working Principle:
- When a conductor moves within a magnetic field, an electromotive force (EMF) is induced in it.
- This induced EMF causes a current to flow in a closed circuit.
- The split-ring commutator ensures that the current flows in one direction, producing DC output.
Parts of a DC Generator:
- Armature: Rotates within the magnetic field and generates EMF.
- Magnetic Field: Produced by field magnets or electromagnets.
- Commutator: Converts alternating current (AC) to direct current (DC).
- Brushes: Maintain electrical contact between the rotating commutator and external circuit.
Uses of DC Generators:
- Used in battery charging systems.
- Employed in small electrical appliances and portable power tools.
- Used in electric traction (trains, trams, and trolleys).
Simple and Understandable Answer:
This is a DC Generator, a device that generates electricity using a rotating coil in a magnetic field.
How does it work?
- When the coil rotates, electricity is produced due to the movement in a magnetic field.
- The special ring (commutator) helps in producing DC current instead of AC.
Where is it used?
- In battery chargers.
- For powering small machines and tools.
- In electric trains and trams.
Solve the following example.
Problem: Heat energy is being produced in a resistance in a circuit at the rate of 100 W. The current of 3 A is flowing in the circuit. What must be the value of the resistance?
Solution:
We use the formula for electrical power:
P = I²R
Where:
- P = Power (100 W)
- I = Current (3 A)
- R = Resistance (to be found)
Rearranging the formula to solve for R:
R = P / I²
Substituting the given values:
R = 100 / (3 × 3)
R = 100 / 9
R ≈ 11.11 Ω
Final Answer:
The required resistance in the circuit is 11.11 Ω.
Solve the following example.
Problem: Two tungsten bulbs of wattage 100 W and 60 W power work on 220 V potential difference. If they are connected in parallel, how much current will flow in the main conductor?
Solution:
We use the formula for electrical power:
P = V × I
Rearranging to find I:
I = P / V
For the first bulb (100 W):
I₁ = 100 / 220
I₁ ≈ 0.4545 A
For the second bulb (60 W):
I₂ = 60 / 220
I₂ ≈ 0.2727 A
Total current in the main conductor:
I = I₁ + I₂
I ≈ 0.4545 + 0.2727
I ≈ 0.7272 A
Final Answer:
The total current flowing in the main conductor is 0.7272 A.
Solve the following example.
Problem: Who will spend more electrical energy? A 500 W TV Set in 30 minutes or a 600 W heater in 20 minutes?
Solution:
We use the formula for electrical energy:
E = P × t
where:
- E = Energy consumed (in Watt-hours or Wh)
- P = Power (in Watts)
- t = Time (in hours)
Step 1: Convert time to hours
For TV Set: 30 minutes = 30/60 = 0.5 hours
For Heater: 20 minutes = 20/60 = 0.3333 hours
Step 2: Calculate Energy Consumption
For TV Set:
E₁ = 500 × 0.5
E₁ = 250 Wh
For Heater:
E₂ = 600 × 0.3333
E₂ = 200 Wh
Final Answer:
The 500 W TV Set consumes 250 Wh, while the 600 W Heater consumes 200 Wh.
Conclusion: The 500 W TV Set consumes more energy than the 600 W heater.
Solve the following example.
Problem: An electric iron of 1100 W is operated for 2 hours daily. What will be the electrical consumption expenses for that in the month of April? (The electric company charges Rs 5 per unit of energy).
Solution:
We use the formula for electrical energy consumption:
E = P × t
where:
- E = Energy consumed (in kWh or units)
- P = Power (in kW)
- t = Time (in hours)
Step 1: Convert Power to Kilowatts (kW)
Power of electric iron: 1100 W = 1.1 kW
Step 2: Calculate Daily Energy Consumption
Daily Energy Consumption (E₁) = 1.1 × 2
E₁ = 2.2 kWh
Step 3: Calculate Monthly Energy Consumption
Since April has **30 days**, total energy consumption:
E (Monthly) = 2.2 × 30
E = 66 kWh (or units)
Step 4: Calculate Total Cost
Cost = 66 × 5
Cost = Rs 330
Final Answer:
The total electrical consumption expense for the electric iron in the month of April will be Rs 330.