Basic Electricity MCQ Quiz - Objective Question with Answer for Basic Electricity - Download Free PDF

Explanation:

The question asks which metal is commonly used for electroplating. The correct answer is option 2, which is Gold. Let's delve into a detailed explanation of why gold is commonly used for electroplating, and analyze the other options provided.

Gold Electroplating

Electroplating is a process that uses electric current to reduce dissolved metal cations so that they form a coherent metal coating on an electrode. Gold electroplating is widely used in various industries due to its unique properties and advantages. Here’s an in-depth look at why gold is commonly used for electroplating:

Explanation:

Voltameter

Definition: A voltameter is an instrument used in laboratories to demonstrate the chemical effect of electric current.

It is an electrochemical device that measures the quantity of electricity (electric charge) through the electrolytic deposition of a substance.

The voltameter is particularly useful in the study of electrolysis and the laws governing it, such as Faraday's laws of electrolysis.

Working Principle: The principle behind a voltameter is based on electrolysis, where an electric current is passed through an electrolyte causing chemical reactions at the electrodes and the separation of elements. The amount of substance deposited or dissolved at the electrodes is directly proportional to the quantity of electricity passed through the electrolyte.

Explanation:

Electrolyte

Definition: An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. Electrolytes are essential in the field of chemistry and play a crucial role in various biological processes.

Types of Electrolytes: Electrolytes can be broadly classified into two categories based on their dissociation in water:

• Strong Electrolytes: These substances completely dissociate into ions in solution, providing a high concentration of ions and thus a high conductivity. Examples include sodium chloride (NaCl), potassium hydroxide (KOH), and hydrochloric acid (HCl).
• Weak Electrolytes: These substances partially dissociate into ions in solution, resulting in a lower concentration of ions and therefore lower conductivity. Examples include acetic acid (CH₃COOH) and ammonia (NH₃).

Explanation:

Electrolytes in Electrochemistry

Definition: An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. The dissolved electrolyte separates into cations and anions, which disperse uniformly through the solvent. Electrolytes are essential for various electrochemical processes, including electrolysis, batteries, and biological functions in living organisms.

Correct Option Analysis:

The correct option is:

Option 3: Salt solution

This option is correct because a salt solution, such as sodium chloride (NaCl) dissolved in water, dissociates into sodium (Na⁺) and chloride (Cl^-) ions. These ions are free to move in the solution, making it an effective conductor of electricity. Therefore, salt solutions are commonly used as electrolytes in various electrochemical processes.

Explanation:

Electrolysis is the process of using an electric current to drive a non-spontaneous chemical reaction. It involves the decomposition of chemical compounds in a solution or molten state when an electric current passes through it. 

Applications:

• Electroplating: Electrolysis is used to deposit a layer of metal onto the surface of another material. For example, gold plating or nickel plating.
• Extraction of Metals: Electrolysis is used in the extraction of reactive metals like aluminum, sodium, and magnesium from their ores.
• Electrolytic Refining: This process is used to purify metals, such as copper and zinc.
• Production of Chemicals: Electrolysis is used in the production of chemicals like chlorine and sodium hydroxide through the electrolysis of brine.
• Hydrogen Production: Electrolysis of water is used to produce hydrogen and oxygen gases.

Dynamo

• A dynamo is a device that converts mechanical energy into electrical energy through the principle of electromagnetic induction. It does not create charge but instead moves existing charges to generate an electric current.

  Now, let's analyze the options:

• Charge –  Incorrect

  • Charge is a fundamental property of matter and cannot be created or destroyed. A dynamo only moves charges to produce current.

• Magnetism – Incorrect

  • A dynamo uses magnetic fields to generate electricity but does not itself generate magnetism.

• Energy – Partially correct but not precise

  • A dynamo converts one form of energy (mechanical) into another (electrical), but it is more accurate to say it generates emf.

• EMF (Electromotive Force) – Correct

  • A dynamo generates emf (electromotive force), which drives the movement of charge and produces current.

• Thus, the correct answer is:

  Option (4) EMF

The correct answer is option 2

Concept : 

Definition:  The amount of charge passing through a conductor in one second is called as current electricity. 

unit of current electricity is

1.  I = q/t , coulomb / sec
2. I = V/R , \(\frac{volt}{\Omega }\)
3. current is also expressed as ampere

The correct answer is Overloading.

• An electric fuse is a safety device used to limit the current in an electric circuit which melts and breaks the circuit whenever there is an excess flow of current through the circuit.
• A fuse is usually a short piece of wire and is installed in a circuit to stop the flow of excessive current.
• The material of the fuse has high resistivity and a low melting point.

Key Points

• Functions of Electric Fuse:
  •  It acts as a barrier between an electric circuit and the human body.
  • It prevents any damage to the electric device by restricting excess current flow.
  • It prevents overloading of current.
  • It prevents the damage caused by the mismatch of the load.
  • It prevents blackouts.

CONCEPT:

• Power: The rate of work done by an electric current is called power. It is denoted by P. The SI unit of power is the watt (W).

Power dissipation is given by:

Power (P) = V I = V2/R = I2 R

Where V is the potential difference across resistance, I is current flowing and R is resistance.

• Voltage (V) is the amount of potential difference between two points.

​EXPLANATION: 

From the above formula of the power, option 1 is correct.

The correct answer is option 1):(bilateral element)

Concept:

• Bilateral elements are said to be  the elements through which the magnitude of the current is independent of the polarity of the supply voltage
• Conduction of current  is in both directions in an element and with the same magnitude
• The V-I characteristics of the Resistor, Inductor and capacitor cannot be affected by voltage
• In the circuit shown below, The magnitude of current (I) flowing through the circuit is always (V/R) irrespective of the polarity of the supply voltage (V). However, the direction of the flow of current will change on supply voltage polarity but the magnitude of current will remain the same. Here, resistance is a bilateral element and the circuit is a bilateral circuit.

Additional Information

• Unilateral elements in an electrical circuit are defined as an element whose V-I characteristics changes on the reversal of polarity of applied voltage.
• A passive element is an electrical component that does not generate power, but instead dissipates, stores, and/or releases it.
• An active element is an element capable of generating electrical energy.

Option 2 is the correct answer: For domestic wiring purposes, circuits are connected in parallel.

• Following are the reasons why in the domestic wiring appliances are connected in a parallel:
  • Individual switching system: When the appliances are connected in parallel individual on and off switching of appliances is possible. But in series circuit switching one appliance on or off will put all other devices on the same model.
  • Voltage: In a parallel circuit the voltage available to all the appliances is the same and therefore uniform power distribution is there.
• Characteristics parallel connection:
  • Voltage is the same across all the loads/resistance/appliances.
  • Current gets divided in the parallel circuits.
  • The reciprocal of total resistance is equal to the sum of reciprocal of individual resistances i.e. \({1 \over R} = {{1 \over R_1}+{1\over R_2}+{1\over R_3}+.......}\)
• Characteristics of series connection:
  • Current is same throughout the circuit.
  • Voltage gets divided among the appliances/ loads/ resistances.
  • The total resistance is equal to the sum of individual resistances, \(R = {R_1+R_2+R_3+........}\)
  • Power strip is connected in series. switching the power strip of switches off all the connected appliances

The correct answer is option 4):(Current)

Concept:

• The rate of flow of charge over time is said to be electric current
• An ampere is the flow of one coulomb through an area in one second
• The unit of electric current is ampere
• If a net charge Q flows across any cross-section of a conductor in time t, then the current I through the cross-section is

             I = \(Q\over t \)

Additional Information

•  Electric power measures the rate of electrical energy transfer by an electric circuit per unit of time
• The voltage is the electric pressure or difference in potential between two points in an electric field.
• Electrical energy is the power an atom's charged particles have to cause an action or move an object. 

The correct answer is option 3

Concept :

active element: active elements are those elements that supply the energy and ability to control the flow of charge and are used for current control and voltage control application. Active sources include sources of voltage and current.

Passive element: Passive elements are elements that store energy. R, L, and C are hence referred to as passive elements.

The correct answer is option 3

Concept :

Electric bulb: Electric bulb is a device that converts electrical energy into heat energy.

• Resistance of Electric bulb R = \(\frac{(Rated voltage )^{2}}{Rated power}\)
• If we consider bulbs as a resistive load we can easily find the current and voltage drop
• Power consumed = i²R
• Power consumed is proportional to the brightness.

Explanation

• ​Resistance in series combination: When two or more resistance is connected one after another such that the same current flow through them called a series combination.

Net resistance or equivalent resistance: when resistance is connected in series then Equivalent Resistance R = R₁ + R₂.

Since all three bulbs are the same rating we can say that all bulbs are the same resistance.

The resistance of one bulb is R and three bulbs are connected in series the overall resistance(R) = 3R.

 R = \(\frac{(Rated \ voltage)^{^{2}} }{rated \ power} = \frac{200^{2}}{60} = \frac{2000}{3} = 3 \times \frac{2000}{3} = 2000\)

 R = 2000 ohm

using ohms law,

 V = IR

 \(I = \frac{V}{R}\)

\(I = \frac{200}{2000}\)

I = .1

Power (P) = i²R = \(.1^{2}\times 2000\) = 20 W

Ampere is a unit of current.

Quantity of electricity (C) = current in amperes (I) × time in seconds (t)

Coulomb (C):

It is the quantity of electricity transferred by a current of one ampere in one second. Another name for the above unit is the ampere-second. A larger unit of the quantity of electricity is the ampere-hour (A.h) and is obtained when the time unit is in hours.

1 A.h = 3600 A.s or 3600 C