Electricity

If the potential difference across a conductor is doubled while keeping other factors constant, the work done in moving the same amount of charge will:

The work done in moving a charge is measured in:

A cell converts ________ energy into electrical energy.

Which of the following is correct regarding the flow of charge?

If $W$ is the work required to move $n$ electrons between two points in a circuit, and $e$ is the magnitude of charge on a single electron, which expression correctly defines the potential difference $V$ across these points?

To get a total current of $1\ A$ when the charge is $10\ C$, the time required is:

In a closed circuit, current flow is possible only when there is a difference in:

If the length of a conductor is increased by $0.1\%$ by stretching it, the percentage increase in its resistance will be:

A technician has only two resistance coils. By using them singly, in series or in parallel, he is able to obtain the resistances of $3, 4, 12$ and $16\,\Omega$. The resistances of the two coils are:

Two copper wires have the same length, but the second has twice the diameter of the first. If the resistance of the first is $4\,\Omega$, the resistance of the second is:

In the given electrical circuit, if the voltage across the battery is $V$ and the current flowing through the circuit is $I$, which of the following expressions correctly represents Ohm's law for the resistor $R$?

The slope of a $V-I$ graph (with $V$ on the y-axis and $I$ on the x-axis) represents:

A voltmeter is always connected in ________ with the circuit element to measure potential difference.

Which of the following materials has the lowest resistivity at room temperature?

Two resistors, $R_1$ and $R_2$, are made of the same material and have the same length, but the cross-sectional area of $R_2$ is twice that of $R_1$. If they are connected in a circuit as shown, how does the resistance of $R_2$ compare to $R_1$?

Two resistors $R_1$ and $R_2$ ($R_1 > R_2$) are connected in parallel. The equivalent resistance $R_p$ will be:

How does the resistance of a semiconductor change with an increase in temperature?

A fuse wire with a radius of $0.2 mm$ blows at a current of $5 A$. If the material of the fuse is kept the same, what should be the radius of the fuse wire to blow at $10 A$, given that the heat produced per second is balanced by the heat lost through the surface?

A potentiometer wire has a length of $10m$ and a total resistance of $20 \Omega$. It is connected in series with a $5V$ battery and a $30 \Omega$ external resistor. What is the potential gradient (voltage drop per unit length) along the wire?

Three resistors of $3 \Omega$, $6 \Omega$, and $9 \Omega$ are connected in a combination such that the total resistance is minimum. This combination is then connected to a $12V$ battery. What is the current through the $3 \Omega$ resistor?

If you have two wires of the same length and material, but wire X is thinner than wire Y, then:

Which of the following determines the resistance of a resistor?

If we use a wire made of an alloy instead of a pure metal, the resistivity is usually:

For a cylindrical conductor, the area of cross-section $A$ is equal to:

Two wires, A and B, are made of different materials and have dimensions as shown in the diagram. If both wires have identical electrical resistance, calculate the ratio of the resistivity of material A ($\rho_A$) to the resistivity of material B ($\rho_B$).

Which of the following is the best conductor of electricity among those listed?

Two wires of the same material have lengths $L$ and $2L$ and cross-sectional areas $4A$ and $A$ respectively. The ratio of their resistances is:

A uniform metallic wire of resistance $R$ is stretched until its length becomes twice its original length. This stretched wire is then cut into three equal segments, and these three segments are connected in parallel to form a new conductor. What is the resistance of this final parallel combination?

A wire of uniform cross-section has resistance $12 \Omega$. It is bent into a circle. The resistance between two points on the circle that subtend an angle of $90^{\circ}$ at the center is:

A metal wire of length $L$ and radius $r$ has resistance $R$. If it is melted and recast into a wire of radius $r/2$, the new length of the wire will be:

Two resistors, $R_1 = 4 \, \Omega$ and $R_2 = 6 \, \Omega$, are connected in series to a $10 \, V$ battery. What is the equivalent resistance of the circuit?

Identify the incorrect statement about parallel combination of resistors:

Which circuit arrangement is preferred for domestic household wiring?

What happens to the total resistance in a circuit when more resistors are added in parallel?

A wire of resistance $12\,\Omega$ is cut into three equal pieces, and these pieces are then connected in parallel. The new resistance is:

In the circuit shown, if the $3\,\Omega$ resistor is removed (open circuit), what happens to the current through the $6\,\Omega$ resistor?

Four resistors each of resistance $R$ are connected to form a square. What is the equivalent resistance across any two adjacent corners?

A designer wants to reduce a $24V$ source to $18V$ across a load resistor of $6 \Omega$. She decides to put another resistor $R_s$ in series with the load. What should be the value of $R_s$, and what will be the total current in the circuit?

Three resistors $R_1 = 2 \Omega$, $R_2 = 3 \Omega$, and $R_3 = 6 \Omega$ are connected in parallel. This entire group is then connected in series with a $4 \Omega$ resistor and a $10V$ battery. What is the power consumed by the $4 \Omega$ resistor?

An electric car's auxiliary system uses a $12V$ battery. It powers a dashboard display ($40 \Omega$) and a cooling fan ($10 \Omega$) connected in parallel. However, a faulty wire adds $2 \Omega$ of resistance in series with the battery before the parallel split. Calculate the potential difference actually available to the fan.

If a current of $0.5\,A$ flows through a lamp for $10$ minutes at $200\,V$, the heat produced is:

What represents the 'rate of consumption of energy'?

Which physical quantity has the unit $Volt \cdot Ampere$?

Heating elements are generally made of alloys rather than pure metals because:

The time $t$ for which current flows is tripled, keeping $I$ and $R$ constant. The heat produced will:

Which of the following is equivalent to $1\ Volt \times 1\ Ampere$?

Two wires of the same material and same length but different radii $r_1$ and $r_2$ ($r_1 > r_2$) are connected in series. Which wire will produce more heat?

Two electric bulbs are rated $P1, V$ and $P2, V$. If they are connected in series across voltage $V$, the total power $P$ is:

An electric kettle rated $500 W, 220 V$ is used to heat water for $30$ seconds. The heat produced is:

If the current through a heater is doubled, and the time for which it is passed is halved, the heat produced will:

If an electric heater is rated $1500 \text{ W}$, how much energy does it consume in $2 \text{ hours}$ in units?

Which formula should be used to calculate power if current and resistance are known?

Total energy consumed by a $100 \text{ W}$ bulb in $2 \text{ hours}$ is:

Which of the following has the highest power rating in a typical household?

Which physical quantity is measured in $V^2\,\Omega^{-1}$?

How many Joules are there in $1\,Watt-hour$?

If the resistance of a circuit is halved and the potential difference is kept constant, the power will:

Which of the following materials would have the highest power dissipation if identical wires are connected to the same voltage source?

An electric bulb is rated $60\ W, 120\ V$. What resistance must be connected in series with this bulb so that it can be used on a $240\ V$ supply without blowing?

A fuse wire of $3\ A$ rating has a diameter of $0.2\ mm$. If we want a fuse wire of the same material to blow at $12\ A$, how should the diameter change (assuming the same length)?

An electric kettle consumes $2.2 kW$ of power when operated at $220 V$. The current is:

Which of the following is correct for $1$ Volt?

The brightness of a bulb depends on its:

How much work is done in moving a charge of $2 C$ across two points having a potential difference of $12 V$?

A circuit initially contains two identical resistors connected in parallel across a constant voltage source. If a third identical resistor is added in parallel to the first two, what is the ratio of the final total power dissipated by the circuit to the initial total power dissipated?

Which of the following does not represent electrical power in a circuit?

A current of $2 A$ flows through a $5 \Omega$ resistor for $1$ minute. The energy dissipated is:

A coil of resistance $100\,\Omega$ is connected to a $200\,V$ source. If the coil is immersed in a liquid of mass $1\,kg$ and specific heat $2000\,J/kg^{\circ}C$, the rise in temperature in $100$ seconds is:

Two metallic wires $A$ and $B$ are of same material. Wire $A$ has length $L$ and radius $r$. Wire $B$ has length $2L$ and radius $2r$. If they are connected in parallel to a $V$ source, the ratio of power $P_A/P_B$ is:

If the voltage across a bulb drops by $1\%$, the power drops by approximately:

According to Ohm's law, if the potential difference across a conductor is doubled while keeping the temperature constant, how will the electric current flowing through it change?

The SI unit of electrical resistance is:

According to Ohm's law, if the temperature remains constant, the current flowing through a conductor is:

What does the potential difference between two points in an electric circuit represent?

In a V-I graph for an Ohmic conductor, the slope of the straight line represents:

If the potential difference across a $12\ \Omega$ resistor is $6\ V$, the current flowing through it is:

Which mathematical expression correctly represents Ohm's Law?

A solar-powered water pump requires a constant potential difference of $24\,V$ to function efficiently. The internal resistance of the motor is $8\,\Omega$. Due to a change in cloud cover, the current drops from $3\,A$ to $1.5\,A$. By how much has the effective potential difference provided by the solar panel dropped, assuming the motor's resistance remains constant?

An industrial heater consists of two heating elements. Element A has a resistance of $20\,\Omega$. When Element B is connected in series with A across a $220\,V$ line, the total current drawn is $5.5\,A$. If the Ohm's Law holds true, what is the potential difference specifically across Element B?

A decorative LED strip operates by passing $300\,mA$ of current through a specific section. If the potential difference across this section is $9\,V$, and the strip is left on for 10 minutes, calculate the total number of electrons that pass through any cross-section of the wire during this time (Charge on 1 electron $\approx 1.6 \times 10^{-19}\,C$).

Two resistors, $R_1 = 4 \, \Omega$ and $R_2 = 6 \, \Omega$, are connected in series to a $10 \, V$ battery as shown in the diagram. Calculate the equivalent resistance of the circuit.

What is the resistance of a lamp if it is the only component connected to a $12 \text{V}$ battery and draws $0.5 \text{A}$ current?

Identify the total resistance of the three $3 \, \Omega$ resistors connected in series as shown in the diagram.

What happens to the total resistance when more resistors are added in a parallel combination?

Three resistors of $2 \, \Omega$, $4 \, \Omega$, and $6 \, \Omega$ are connected in series. Find the current flowing through the circuit if the battery is $12 \text{V}$.

Calculate the equivalent resistance between points A and B for the circuit shown.

If a wire of resistance $R$ is cut into two equal halves and connected in parallel, the new resistance will be:

An electrician is designing a lighting system for a large hall. He connects two identical lamps, each having a resistance of $R_L = 20\,\Omega$, in parallel. To protect the circuit, he connects this parallel combination in series with a fixed resistor $R_s = 5\,\Omega$ and a $12\,V$ battery. However, he notices that one of the lamps has a higher resistivity filament although its dimensions are identical to the other, making its actual resistance $30\,\Omega$ instead of $20\,\Omega$. What is the new total current flowing from the battery in this modified circuit?

A solar power enthusiast has two identical cylindrical copper rods of resistance $R$ each. He wants to compare the resistance of a single rod with a new configuration where he cuts one rod into two equal halves by length and joins them side-by-side (in parallel). If this new 'thick' half-length rod has resistance $R'$, what is the ratio $R/R'$?

A smart home lighting system uses three identical decorative lamps, each of resistance $30 \Omega$. The system is designed such that two lamps are in parallel, and this combination is connected in series with the third lamp and a $12 V$ DC power source. Calculate the total current drawn from the source and the potential difference across the third lamp.

If the current $I$ in a circuit is $1 A$ and the voltage $V$ is $1 V$, the power $P$ is:

What is the equivalent of $1$ Kilowatt in Watts?

The power of a circuit is $10 W$ when the current is $2 A$. What is the resistance?

Calculate the power consumed by a resistor of $5 Ω$ when a potential difference of $10 V$ is applied across it.

A student conducts an experiment to observe the heating effect of electric current. In the first setup, a current $I$ passes through a resistor $R$ for a time $t$, producing an amount of heat $H$. In the second setup, the student replaces the resistor with one of value $R/2$ and doubles the current to $2I$. What will be the amount of heat produced in the second setup during the same time interval $t$?

Two resistors of $4\ \Omega$ and $6\ \Omega$ are connected in parallel. If the power dissipated in the $4\ \Omega$ resistor is $36\ W$, what is the power dissipated in the $6\ \Omega$ resistor?

A wire of resistance $R$ is stretched to double its length. If it is then connected to the same voltage source, how does the power dissipated change?

A wire of resistance $R$ is stretched so that its length increases by $100\%$. If it is then connected to the same voltage source, the power dissipated becomes:

An electric bulb is connected to a $220\,V$ generator. The current is $0.50\,A$. What is the power of the bulb?

If the resistance of an electric circuit is halved and the potential difference is doubled, the power will become:

The potential difference is measured by a voltmeter which is always connected in:

Which of the following does NOT represent electrical power?

If the current through a resistor is doubled, the heat produced becomes:

What is the direction of conventional current flow?

In the circuit shown below, a $12\ V$ battery is connected to a network of three resistors. What is the total current ($I$) flowing through the $4\ \Omega$ resistor?

What is the equivalent resistance of two resistors $R_1$ and $R_2$ when they are connected in parallel?

The heating element of an electric toaster is usually made of:

A $220\text{ V, } 1000\text{ W}$ heater is used for $2$ hours daily. What is the cost of using it for a week if the cost per unit is $Rs. 5$?

If the length of a conductor is doubled and its area of cross-section is tripled, the new resistance will be how many times the original resistance?

Two metallic wires A and B are connected in series. Wire A has resistance $R$ and wire B has resistance $2R$. If $10\text{ J}$ of heat is produced in wire A in a certain time, how much heat is produced in wire B in the same time?

A steady current of $0.5$ A flows through an electric bulb for $10$ minutes. Calculate the amount of electric charge that flows through the circuit.

If 'I' is current, 'Q' is charge and 't' is time, which formula is correct?

Which component is represented by the following symbol in a circuit diagram: a long line and a short thick line?

Electric current is the rate of flow of:

In the given circuit diagram, which of the following statements correctly describes the direction of conventional current and the flow of electrons?

What is the total charge flowing through a circuit if a current of $250$ mA flows for $2$ minutes?

If $3000$ C of charge flows through a heater in $1$ hour, what is the current?

An experimental electric vehicle toy uses a circuit where a current of $0.8$ A flows when the switch is closed. A student observes the circuit for a period of time and calculates that $1440$ Coulombs of charge have moved through the motor. For how many minutes was the switch kept in the 'ON' position to allow this specific amount of charge to flow?

In a custom-built lighting display, a thin filament lamp is connected to a battery. A micro-ammeter connected in the circuit shows a constant reading of $250$ mA. If the display is left on for exactly $1$ hour and $20$ minutes during a show, what is the total magnitude of electric charge that has passed through the lamp filament?

A laboratory technician is testing a sensor circuit. The circuit consists of a DC power source and a conductive path where a total charge of $7.5 \times 10^{20}$ electrons flows through a specific cross-section of the wire every $2$ minutes. Using the elementary charge $e = 1.6 \times 10^{-19}$ C, calculate the steady electric current indicated by the ammeter in the circuit.

Potential difference makes the electrons:

Which of the following describes 1 Volt?

Work done to move $0.5 C$ charge through a PD of $10 V$ is:

Voltmeter is a device used to measure: