Magnetic Effects of Electric Current

A compass needle is a small:

What is the nature of the magnetic field lines between two unlike poles?

The magnetic field is strongest at the _________ of a current-carrying circular loop.

The magnetic field lines of a solenoid are very similar to those of a:

A student is using a small compass to map the magnetic field lines around a permanent bar magnet. According to the standard properties of magnetic field lines, what is the geometric relationship between the field line and the direction in which the North pole of the compass needle points at any specific point $P$?

If current flows clockwise in a loop, the magnetic field lines at the center of the loop point:

The magnetic field lines are always _____ to the surface of a magnet at the poles.

The magnetic field produced by a solenoid is similar to that of a bar magnet. However, a key difference is:

If a bar magnet is cut into two equal halves along its length, the magnetic field line pattern of each half will:

When a current is passed through a circular loop, the magnetic field lines near the wire are:

Which of the following determines the direction of the magnetic field in a loop?

Magnetic field lines are continuous curves that:

The core of an electromagnet should have:

The magnetic field at a point near a straight wire is $0.5$ Tesla. If the current is tripled, the field strength becomes:

In a solenoid, the magnetic field lines emerge from which end?

The magnetic field produced by a straight current-carrying conductor at a given point is directly proportional to:

Two parallel wires carry current in the same direction. They will:

A circular conductor is formed by joining two semicircular wires, $X$ and $Y$, in parallel. Both wires are made of the same material, but wire $X$ has a larger cross-sectional area than wire $Y$. Current $I$ enters at one junction and leaves at the opposite junction. If the current flows clockwise through $X$ and anticlockwise through $Y$, which of the following best describes the net magnetic field at the center of the circle?

A current $I$ flows through a circular loop of radius $R$. The magnetic field at the center is $B$. If the current is kept the same but the loop is bent into a coil of 2 turns of radius $R/2$, the new magnetic field at the center is:

Which of the following describes the magnetic field lines near a long straight wire carrying current?

In the context of a solenoid, the term 'n' usually refers to:

To get a very strong magnetic field inside a solenoid, one should use:

The magnetic field lines produced by a solenoid are similar to those of a:

Magnetic field lines around a straight current-carrying conductor are in the form of concentric circles. As we move away from the conductor, these circles:

A student has a long solenoid of length $L$ with $N$ total turns. When a current $I$ flows through it, the magnetic field strength at its center is $B$. If the student cuts the solenoid into two equal halves and passes the same current $I$ through one of the halves, the magnetic field at the center of this new solenoid will be:

In an electromagnet, the core is made of soft iron. If the current is switched off, what happens to the magnetism of the core?

The magnetic field $B$ at the center of a circular coil is $0.1 \text{ T}$. If the number of turns is tripled and the current is doubled, the new field will be:

An ideal solenoid is one where the length is much larger than the radius ($L >> R$). For such a solenoid, the magnetic field outside is:

The direction of the magnetic field at any point on the axis of a current-carrying solenoid is:

If a solenoid is wound with two layers of wire such that the current in the second layer flows in the opposite direction to the first, the net magnetic field inside will be:

A positively charged particle is moving upwards. A magnetic field is applied towards the North. The direction of force is towards:

If the current in a wire is flowing towards the observer, and the magnetic field is directed from left to right, what is the direction of the force?

The 'Middle Finger' in Fleming's Left-Hand Rule represents:

The force on a current-carrying conductor in a magnetic field was first mathematically described by:

A flexible copper wire is suspended between the poles of a strong permanent magnet. When a DC source is connected, the wire is observed to deflect towards the right. If the student replaces the DC source with an AC source of $50\text{ Hz}$, which of the following will be the most likely observation?

The direction of current is taken as the direction of flow of:

If a current-carrying conductor is rotated in a magnetic field so the angle changes from $90^{\circ}$ to $45^{\circ}$, the force on it will:

A wire is carrying a current from South to North. The Earth's magnetic field at that location has a horizontal component directed from South to North and a vertical component directed downwards. The force on the wire is due to:

The direction of the force on a current-carrying wire in a magnetic field is always:

A magnetic field is directed out of the page. An electron moves into the page. The force on the electron is:

If the current flows out of the page and the magnetic field is towards the top of the page, the force is towards the:

Fleming's Left-Hand Rule helps to understand the working of which part of an electric motor?

What is the force on a conductor if it is placed in a region with no magnetic field?

If the forefinger points in the direction of the magnetic field and the thumb in the direction of motion, then the middle finger points in the direction of:

A straight copper wire is placed in a uniform magnetic field. The current in the wire is flowing directly away from the observer (into the plane of the paper). If the magnetic field lines are directed from the bottom of the page toward the top, in which direction will the wire experience a magnetic force?

The direction of force on a current-carrying conductor in a magnetic field is reversed if:

A current flows North and the force on the wire is West. The magnetic field must be directed:

A current-carrying conductor is placed in a magnetic field. If the direction of the magnetic field is made parallel to the direction of the current, the force on the conductor will be:

Which of the following is NOT a necessary condition for a particle to experience a force in a magnetic field?

A proton enters a magnetic field from the East and is deflected towards the North. The magnetic field is directed:

The potential of the neutral wire is:

The direction of force on a current-carrying conductor in a magnetic field is given by:

Which of these devices does NOT work on the magnetic effect of current?

To increase the strength of an electromagnet, we can:

A long straight wire carries a constant direct current. At a distance of $10\text{ cm}$ from the wire (Point A), the magnetic field strength is measured as $0.4\text{ T}$. If the measurement is taken at a distance of $20\text{ cm}$ from the wire (Point B), what will be the new magnetic field strength?

A square conducting loop $PQRS$ is placed horizontally on a table. A direct current flows through the loop in the direction $P \rightarrow Q \rightarrow R \rightarrow S \rightarrow P$ as viewed from above. What is the direction of the magnetic field produced at the center of the loop?

The direction of magnetic field produced by a current-carrying conductor can be reversed by:

A current $I$ flows through a very long solenoid. If we move from the axis towards the inner wall of the solenoid (well away from the ends), the magnetic field:

What is the force on a charge $q$ moving with velocity $v$ parallel to the magnetic field $B$?

Overloading in a circuit can occur when:

In an AC generator, the maximum current is induced when the coil is:

For an AC with frequency $f$, the time for one complete cycle is $T$. The relationship is:

Which type of current is represented by a straight line graph parallel to the time axis?

Which property of AC allows the use of transformers?

In an alternating current (AC) circuit, the direction of the flow of charge reverses periodically. Which of the following best describes the physical behavior of individual electrons within a conductor connected to such a source?

A generator's armature is connected to a steam turbine that rotates at a steady rate of $2400$ revolutions per minute (rpm). Assuming each rotation produces one complete cycle of induced current, what is the frequency of the generated alternating current (AC)?

In an AC circuit, the direction of the magnetic field produced by the wire:

What is the instantaneous value of an AC current ($50\text{ Hz}$) at $t = 1/200\text{ seconds}$ after it passes through zero?

How does the use of a soft iron core in the armature of an AC generator improve its performance?

In a domestic circuit, the live wire and neutral wire have a potential difference that varies. What is the potential of the neutral wire relative to the earth?

What is the frequency of the current that reverses direction every $0.01$ seconds?

The time period for one cycle of 60 Hz AC is approximately:

If the frequency of AC is 0 Hz, the current is effectively:

Which of the following is true for Alternating Current?

If we use a commutator instead of slip rings in an AC generator, the output becomes:

The conversion of mechanical energy into electrical energy in the form of AC is based on the principle of:

In an AC generator, the magnitude of the induced EMF is maximum when the plane of the coil is:

If the number of poles in an AC generator is doubled and the rotational speed is also doubled, the frequency of the output AC will:

The time period of an AC is $T$. What is the time interval between the first and the fourth time the current becomes zero?

At $t = 0.005$ s in a $50$ Hz AC cycle starting from zero, the current is:

In a domestic electric circuit, what is the standard color of the insulation for the earth wire as per international conventions followed in India?

If an appliance has a metal body, which wire must be connected to the body for safety?

The main purpose of a three-pin plug is to:

Domestic appliances are connected in parallel because it ensures:

In domestic wiring, the 'main switch' is used to:

An MCB (Miniature Circuit Breaker) works on the principle of:

What happens if a fuse of $5\text{ A}$ rating is used in a circuit where a $2\text{ kW}$ heater operates at $220\text{ V}$?

A homeowner installs a modern domestic circuit consisting of a $220\text{ V}$ mains supply and several appliances. In the kitchen, a microwave rated at $2.2\text{ kW}$ and an electric kettle rated at $1.1\text{ kW}$ are connected to the same $15\text{ A}$ power circuit. If a safety fuse is connected in series with the live wire as shown in the diagram, and a fault occurs causing a short circuit between the live and neutral wires, which of the following statements best describes the behavior of the circuit and the safety mechanism?

A student sets up a model of a domestic circuit. He wants to ensure that if a fault occurs in one room's lighting, the other rooms remain unaffected. Which configuration should he use for the appliances and the safety fuse for the whole house?

In a residential wiring setup, an electrician accidentally connects the neutral wire and the live wire directly without any load in between while installing a new socket. What is the most likely physical outcome of this event, and why?

While magnetic field lines emerge from the North pole and merge at the South pole outside a magnet, what is the direction of these field lines inside the bar magnet?

Magnetic field lines are drawn such that they enter the magnet at which pole?

If a bar magnet is broken into two pieces, each piece will have:

Which rule helps in finding the direction of the magnetic field around a straight conductor?

A bar magnet is broken into two equal pieces: Piece $X$ (the left half) and Piece $Y$ (the right half). If the North pole of the original magnet was on its left side, what is the direction of the magnetic field lines inside Piece $X$?

Two long parallel wires are placed vertically. Wire 1 carries a current $I$ in the upward direction, and Wire 2 carries an equal current $I$ in the downward direction. Which of the following statements correctly describes the net magnetic field at the midpoint between these two wires?

What happens to the magnetic field at the center of a circular loop if the radius of the loop is increased while keeping the current constant?

What is the relationship between the work done in moving a magnetic pole along a closed magnetic field line and the nature of the magnetic field?

A student places two bar magnets side-by-side with like poles adjacent. How do the field lines behave in the space between the two magnets?

If the Earth's core suddenly stopped its current-like motion, what would happen to the magnetic field lines around the planet?

In the motor effect, the electrical energy is converted into:

What is the direction of the force on a proton moving towards the top of the page in a magnetic field directed into the page?

To find the direction of force on a current-carrying conductor, we use the left hand and keep the fingers:

A charged particle moves at an angle of $180^\circ$ to the magnetic field lines. The force on the particle is:

An alpha particle (a positively charged particle) is projected horizontally towards the South. It is observed to be deflected towards the East by a uniform magnetic field. According to Fleming's Left-Hand Rule, what is the direction of the magnetic field?

Which of the following describes the thumb in Fleming's Left-Hand Rule?

An electron is moving towards the East in a magnetic field directed towards the North. The force on the electron is:

If the current in a conductor is $5$ A and it is placed in a $0.5$ T field such that it experiences a force of $2.5$ N per meter, the angle between the conductor and the field is:

A current-carrying wire is placed in a magnetic field directed at $180^\circ$ to the current. The force experienced is:

A conductor of length $L$ is carrying a current $I$ in a magnetic field $B$. If the conductor is rotated so it is parallel to $B$, the force becomes:

A current reverses its direction every $0.02\text{ seconds}$. What is the frequency of this AC?

If the frequency of an AC generator is $10\text{ Hz}$, how many full cycles are completed in $1$ minute?

The standard frequency of AC in India is $50\text{ Hz}$. What is the ratio of this frequency to the frequency of DC?

What is the time period of an AC with a frequency of $100\text{ Hz}$?

A straight conducting wire is held horizontally along the North-South direction and placed directly above a magnetic compass needle. If a direct current ($I$) is passed through the wire from the South to the North, in which direction will the North pole of the compass needle deflect?

If the frequency of AC is $f$, the number of zero-crossings per second is:

A student observes that a lamp connected to an AC source appears to be continuously glowing. This is because the frequency of the AC is:

In a $100\text{ Hz}$ AC supply, what is the time difference between the $1$st positive peak and the $10$th positive peak?

A specific device requires AC with a period of $0.01\text{ s}$. If the supply available is $50\text{ Hz}$, what must be done to the supply frequency to match the device requirement?

If an AC generator rotates at $50$ revolutions per second, how many times per second does the induced EMF reach its maximum magnitude?

Which of the following is NOT a source of direct current?

If the current flows in a clockwise direction in a circular loop, the face of the loop acts as a:

To convert an AC generator into a DC generator, which component must be changed?

The magnetic field lines are closest together at:

Maxwell’s Right-Hand Grip Rule (also known as the Corkscrew Rule) is used to find the direction of the magnetic field. In this rule, if the downward movement of the corkscrew represents the direction of current, what does the rotation of the handle represent?

A straight conductor of length $L$ carrying a current $I$ is placed perpendicular to a uniform magnetic field $B$. If the length of the conductor is increased to $2L$ while $I$ and $B$ are kept constant, the magnetic force ($F$) acting on the conductor will:

The following diagram illustrates the change in direction of a specific type of current over time. Based on the pattern shown, what can be concluded about this current?

Which of the following factors does NOT affect the magnitude of force on a current-carrying conductor in a magnetic field?

The direction of magnetic field produced by a straight current-carrying conductor is given by:

Galvanometer is a device used to:

If you reverse the poles of a magnet, the direction of the magnetic field lines will:

Inside a bar magnet, the magnetic field lines move from:

The magnetic field is strongest where the field lines are:

A current-carrying straight wire produces a magnetic field. The field lines are:

The provided diagram illustrates a segment of a magnetic field line in a specific region. If a student places a magnetic compass at Point $X$, in which direction will the South pole of the compass needle point relative to the field line's arrow?

A bar magnet is placed on a horizontal table. A small compass is positioned at Point $P$, which lies on the perpendicular bisector of the magnet's axis (the equatorial line), as shown in the diagram. According to the properties of magnetic field lines, in which direction will the North pole of the compass needle point when placed at $P$?

The strength of a magnetic field ($B$) is a measure of:

If we define the magnetic field strength at a point as $B$, how does the work done in moving a magnetic pole around a closed loop in this field relate to the field lines?

At what angle does a magnetic field line enter or leave the surface of a bar magnet?

What is the result of placing two bar magnets end-to-end with opposite poles (N-S) touching?

The magnetic field at a point near a current-carrying wire is _______ to the current.

What happens to the magnetic field strength if the number of turns in a solenoid is increased?

Soft iron is used as a core in electromagnets because it _______.

Magnetic field lines are _______ curves.

A student sets up a circuit consisting of a long solenoid, a battery, and a rheostat (variable resistor). If the student adjusts the slider of the rheostat to significantly decrease the resistance in the circuit, what will happen to the pattern of the magnetic field lines inside the solenoid?

A circular loop of wire is placed flat on a horizontal table. A constant current $I$ flows through the loop in the clockwise direction when viewed from above. Which of the following correctly describes the direction of the magnetic field at point $A$ (located exactly at the center of the loop) and point $B$ (located on the table, but outside the loop)?

What type of current is supplied to our homes in India?

The magnetic field strength at a point on the axis of a circular current loop is:

A domestic circuit has a fuse rated at $5 \text{ A}$. If an electric iron of $2 \text{ kW}$ is operated at $220 \text{ V}$, the fuse will:

What happens to the deflection of a galvanometer when a magnet is held stationary inside a coil?

Fleming's Left-Hand Rule helps to find the direction of:

The unit of current is:

A magnetic field exerts no force on:

Electric motors convert:

The force on a current-carrying conductor in a magnetic field is a vector quantity. This means it has:

The direction of conventional current is:

In the aluminum rod experiment, the rod is connected to the circuit using flexible wires to:

According to the Fleming's Left Hand Rule, the thumb, forefinger, and middle finger should be placed:

Which of the following is NOT a factor affecting the magnitude of the force on a current-carrying conductor in a magnetic field?

A beam of electrons is moving horizontally from West to East. A magnetic field is acting vertically upwards. The force on the beam will be towards:

A safety device used in domestic circuits to prevent damage due to short-circuiting or overloading is the electric fuse. How is it connected in the circuit?

In a domestic electric circuit, which color insulation is traditionally used for the 'live' (phase) wire in modern standard coding followed in India?

Which wire in the domestic circuit has zero potential relative to the earth?

The frequency of AC supply in Indian domestic circuits is:

Which of the following is NOT a component of a standard domestic circuit box?

Overloading in domestic circuits can occur when:

A fuse wire should have:

In a domestic 220V supply, two different circuits are usually provided: 15A and 5A. If a device with a resistance of $11 \Omega$ is plugged into the 5A circuit, what will happen, and what is the scientific reason?

Consider a domestic circuit where multiple sockets are connected in parallel. If one socket develops a short circuit (live wire touches neutral wire directly), why does the entire house lose power even if other appliances are working fine?

A homeowner observes that whenever a heavy motor starts, the lights in the house momentarily dim. This happens because the heavy motor draws a high starting current. If the motor is connected in parallel with the lights, why does this dimming occur?