In an electric circuit when electrons move from low to the high potential they will:

When electrons move from a low to a high potential, they gain energy because they are moving against the electric field.

In an electric circuit an ammeter is always connected in:

An ammeter is always connected in series to measure the current flowing through the circuit.

Resistance of a conductor does not depend on:

The resistance of a conductor does not depend on its density. It depends on length, cross-sectional area, and resistivity.

Ohm's law states that:

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points.

The condition when the resistance of a circuit is zero is known as:

A short circuit is a condition where the resistance of a circuit becomes zero, allowing a large current to flow.

The condition for the validity of Ohm's law is that the:

Ohm's law is valid only if the temperature remains constant, as resistance can vary with temperature.

Ohm's law is not applicable to:

Ohm's law is not applicable to semiconductors because their resistance varies non-linearly with voltage and current.

Two resistances of 6Ω and 12Ω are connected in parallel. Their net resistance is______

The net resistance \( R \) of two resistors \( R_1 \) and \( R_2 \) in parallel is given by \( \frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2} \). Thus, \( \frac{1}{R} = \frac{1}{6} + \frac{1}{12} = \frac{1}{4} \), so \( R = 4Ω \).

The property of a body to oppose the flow of electric charge through it is called electric ________

The property of a body to oppose the flow of electric charge through it is called electric resistance.

Which of the following is the purpose of connecting a battery in an electric circuit?

A battery is connected in an electric circuit to maintain a constant potential difference across the conductor, ensuring a steady flow of current.

What is a steady current?

A steady current refers to a continuous and constant flow of free electrons in a conductor.

Which formula defines electric current?

Electric current is defined as the amount of charge \( Q \) passing through a point in a circuit per unit time \( t \), given by \( I = \frac{Q}{t} \).

What is Direct Current (DC)?

Direct Current (DC) is an electric current that flows in one direction with a constant magnitude.

What is Alternating Current (AC)?

Alternating Current (AC) is an electric current that reverses its direction many times per second, typically used in household power supply.

What does potential difference refer to?

Potential difference refers to the difference in electrical potential energy per unit charge between two points in an electric circuit.

What is Electromotive Force (EMF)?

Electromotive Force (EMF) is the energy per unit charge imparted by an energy source such as a battery or generator.

Ohm’s Law is expressed as:

Ohm’s Law states that the voltage \( V \) across a conductor is directly proportional to the current \( I \) flowing through it, expressed as \( V = IR \).

What is conductance?

Conductance is the measure of how easily electrical current can pass through a material, and it is the reciprocal of resistance.

In a series combination of resistors, the total resistance is:

In a series combination of resistors, the total resistance is the sum of the individual resistances.

In a parallel combination of resistors, the total resistance is:

In a parallel combination of resistors, the total resistance is given by the reciprocal of the sum of the reciprocals of the individual resistances.

What does electric power represent in a circuit?

Electric power represents the rate at which electrical energy is transferred or converted per unit time in a circuit.

Joule’s Law tells us that the heat produced is proportional to:

Joule’s Law states that the heat produced in a conductor is proportional to the square of the current \( I \), the resistance \( R \), and the time \( t \), expressed as \( H = I^2 R t \).

What is a thermistor?

A thermistor is a type of resistor whose resistance varies significantly with temperature, making it useful for temperature measurement and control.

What is the function of a Light-Emitting Diode (LED)?

A Light-Emitting Diode (LED) is a semiconductor device that emits light when an electric current flows through it.

What does an LDR (Light Dependent Resistor) do?

An LDR (Light Dependent Resistor) changes its resistance based on the intensity of light it is exposed to, decreasing resistance with increasing light intensity.

What does a galvanometer measure?

A galvanometer is an instrument used to detect and measure small electric currents.

What is the use of an ammeter?

An ammeter is an instrument used to measure the electric current in a circuit, typically in amperes.

A voltmeter is used to measure:

A voltmeter is an instrument used to measure the potential difference (voltage) between two points in an electric circuit.

What was used by Tesla to light up fluorescent lamps wirelessly?

Nikola Tesla used a Tesla coil to demonstrate wireless transmission of electrical energy, lighting up fluorescent lamps without wires.

How far were the lamps placed from the power source in Tesla's experiment?

In Tesla's wireless transmission experiments, the lamps were placed approximately 25 miles away from the power source.

What causes the bulb to light up in Tesla's wireless electricity demonstration?

The bulb lights up due to the magnetic field emitted by the Tesla coil, which wirelessly transmits electrical energy.

In electronic current, the flow of current is from:

In electronic current, the flow of current is from the negative terminal to the positive terminal, which is the direction of electron flow.

Which type of current flows only in one direction?

Direct current (DC) is the type of current that flows only in one direction.

What is the frequency of alternating current in most power stations?

The frequency of alternating current (AC) in most power stations is 50 Hz, though it can be 60 Hz in some countries like the United States.

What is meant by potential difference?

Potential difference refers to the difference in electrical potential energy per unit charge between two points in an electric field.

What is the unit of potential difference in the SI system?

The unit of potential difference in the SI system is the volt (V).

How is one volt defined?

One volt is defined as the potential difference that would move one coulomb of charge with one joule of energy.

What is another common name for potential difference?

Another common name for potential difference is voltage.

How is electromotive force (EMF) defined?

Electromotive force (EMF) is defined as the energy per unit charge supplied by a source to move charges from a lower potential energy to a higher potential energy.

What is the SI unit of EMF?

The SI unit of electromotive force (EMF) is the volt (V).

What is the unit of EMF in the centimeter-gram-second (CGS) system?

The unit of electromotive force (EMF) in the centimeter-gram-second (CGS) system is the statvolt.

Who discovered the relationship between voltage and current known as Ohm's Law?

George Simon Ohm discovered the relationship between voltage and current, which is known as Ohm's Law.

According to Ohm’s Law, current is directly proportional to:

According to Ohm’s Law, the current through a conductor is directly proportional to the potential difference (voltage) across it.

What is the correct formula representation of Ohm’s Law?

The correct formula representation of Ohm’s Law is \( V = IR \), where \( V \) is voltage, \( I \) is current, and \( R \) is resistance.

What does the constant 'K' represent in the equation \( I = KV \)?

In the equation \( I = KV \), the constant 'K' represents conductance, which is the reciprocal of resistance.

What is the SI unit of resistance?

The SI unit of resistance is the ohm (Ω).

Ohm’s Law is only valid under which condition?

Ohm’s Law is only valid under the condition that the temperature remains constant, as resistance can vary with temperature changes.

Which of the following is a non-ohmic device?

A diode is a non-ohmic device because it does not follow Ohm's Law. Its resistance changes with the direction and magnitude of the current.

Which of the following is NOT true about Ohm’s Law?

Ohm’s Law does not apply directly to capacitive and inductive circuits because these components introduce reactance, which affects the relationship between voltage and current.

How much voltage will be dropped across a 50 KΩ resistor with 300 μA current?

Using Ohm's Law \( V = IR \), the voltage drop is \( V = (300 \times 10^{-6} \, \text{A}) \times (50 \times 10^3 \, \Omega) = 15 \, \text{V} \).

What is the formula given by Ohm’s law?

The formula given by Ohm’s law is \( V = IR \), where \( V \) is voltage, \( I \) is current, and \( R \) is resistance.

The unit of electrical resistance is:

The unit of electrical resistance is the ohm (Ω).

What does electrical resistance measure in a circuit?

Electrical resistance measures the opposition to the flow of electric charge in a circuit.

Resistance is directly proportional to:

Resistance is directly proportional to the length of the conductor. As the length increases, the resistance also increases.

Which of the following correctly represents the formula for resistance in terms of resistivity?

The formula for resistance \( R \) in terms of resistivity \( \rho \), length \( L \), and cross-sectional area \( A \) is \( R = \frac{\rho L}{A} \).

What is the unit of resistivity?

The unit of resistivity is the ohm-meter (Ω·m).

Which material will have a higher resistivity?

Insulators have higher resistivity compared to conductors and semiconductors, as they strongly oppose the flow of electric charge.

In metallic conductors, how does resistance change with temperature?

In metallic conductors, resistance increases with an increase in temperature due to increased atomic vibrations that impede electron flow.

What is a series combination of resistors also known as?

A series combination of resistors is also known as a voltage divider because the voltage across each resistor is a fraction of the total voltage supplied.

In a series circuit, how many paths are there for current to flow?

In a series circuit, there is only one path for current to flow through all the components.

What is the total or equivalent resistance (Re) in a series circuit?

In a series circuit, the total or equivalent resistance \( R_e \) is the sum of all individual resistances.

What happens in a series circuit if one component stops working?

In a series circuit, if one component stops working, the entire circuit stops working because the current has only one path and it is interrupted.

In a series connection, how is the total voltage related to individual voltages?

In a series connection, the total voltage is the sum of the individual voltages across each component.

What is the equivalent resistance in a parallel circuit given by?

The equivalent resistance \( R_e \) in a parallel circuit is given by the reciprocal of the sum of the reciprocals of the individual resistances: \( \frac{1}{R_e} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} \).

Which of the following is true about voltage in a parallel circuit?

In a parallel circuit, the voltage remains the same across all resistors because each resistor is connected directly across the voltage source.

In the example of three resistors in series (100Ω, 400Ω, 200Ω), what is the total resistance?

The total resistance in a series circuit is the sum of the individual resistances: \( 100Ω + 400Ω + 200Ω = 700Ω \).

What is the formula to calculate energy in kilowatt-hours (kWh)?

The formula to calculate energy in kilowatt-hours (kWh) is \( \text{Energy (kWh)} = \frac{\text{Power (W)} \times \text{Time (hr)}}{1000} \).

What does the term Electric Power refer to in a circuit?

Electric power refers to the rate at which electrical energy is transferred or converted per unit time in a circuit.

What is the correct mathematical expression for electric power (P)?

The correct mathematical expression for electric power \( P \) is \( P = IV = I^2R = \frac{V^2}{R} \).

In which unit is electrical energy measured?

Electrical energy is measured in joules (J).

According to Joule's Law, the heat produced (H) in a conductor is directly proportional to:

According to Joule's Law, the heat produced \( H \) in a conductor is directly proportional to the square of the current \( I \), the resistance \( R \), and the time \( t \), expressed as \( H = I^2 R t \).

What is the significance of Joule’s Law in electrical circuits?

The significance of Joule’s Law in electrical circuits is that it quantifies the amount of heat generated when an electric current flows through a conductor.

What is the potential difference across a 4-ohm resistor if 100J of heat is produced in 1 second?

Using Joule's Law \( H = I^2 R t \), we find \( 100J = I^2 \times 4Ω \times 1s \). Solving for \( I \) gives \( I = 5A \). Then, using \( V = IR \), the potential difference \( V = 5A \times 4Ω = 20V \).

What is the primary function of a resistor?

The primary function of a resistor is to provide a specified resistance in a circuit, which can be used to control the flow of electrical current.

What does a battery convert into electrical energy?

A battery converts chemical energy into electrical energy through electrochemical reactions.

Which component converts sound energy into electrical signals?

A microphone is a component that converts sound energy into electrical signals.

What happens to the resistance of an LDR when light increases?

The resistance of an LDR (Light Dependent Resistor) decreases when the light intensity increases.

LDRs are mostly used in:

LDRs are mostly used in automatic security lights, where they help in detecting light levels to switch the lights on or off.

Which device is temperature sensitive?

A thermistor is a device that is sensitive to temperature changes, altering its resistance as the temperature changes.

The instrument used to measure very small currents is:

A galvanometer is an instrument used to detect and measure very small electric currents.

Ammeter is a modified form of which instrument?

An ammeter is a modified form of a galvanometer, designed to measure larger currents.

In an Ammeter, a shunt resistance is connected:

In an ammeter, a shunt resistance is connected in parallel to allow most of the current to bypass the galvanometer, enabling measurement of larger currents.

A voltmeter measures:

A voltmeter is an instrument used to measure the potential difference (voltage) between two points in an electric circuit.

To convert a Galvanometer into a Voltmeter, a high resistance is connected:

To convert a galvanometer into a voltmeter, a high resistance is connected in series to limit the current flow and measure potential difference.

Which wire carries no current but is used for safety?

The earth wire carries no current under normal conditions but is used for safety to prevent electric shock by grounding any leakage current.

Electrical appliances in homes are connected in:

Electrical appliances in homes are connected in parallel so that each appliance can operate independently at the same voltage.

Which device cuts off current if it exceeds a safe value?

A fuse is a safety device that cuts off the current in a circuit if it exceeds a safe value, preventing damage or fire hazards.

Circuit breakers are used in place of:

Circuit breakers are used in place of fuses to provide overcurrent protection that can be reset, unlike fuses which need replacement after they blow.

A bimetallic strip in a circuit breaker reacts to:

A bimetallic strip in a circuit breaker reacts to heat generated by excessive current, causing it to bend and trip the circuit breaker.