Magnetism and Iron Filing Interaction

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What is the primary function of the Earth's magnetic field in relation to the solar wind?

To protect us from the solar wind by deflecting and concentrating the harmful particles at the poles

In what direction do magnetic field lines point?

From the north pole to the south pole

What is represented by the concentrated field lines at the poles of a bar magnet?

The strongest part of the magnetic field

What is the purpose of a toroidal container in nuclear fusion?

To generate a near uniform circular magnetic field to fuse high energy protons Signup and view all the answers

What is the result of the interaction between the solar wind's magnetic field and the Earth's magnetic field?

The deflection and concentration of the harmful particles at the poles, causing the aurora borealis and the aurora australis Signup and view all the answers

What is the difference between magnetic flux density and magnetic field strength?

There is no difference; they are interchangeable terms Signup and view all the answers

What is an example of a near uniform magnetic field?

The field between the poles of a horseshoe magnet Signup and view all the answers

What is the shape of the container used to generate a uniform magnetic field in nuclear fusion?

Toroidal (doughnut-shaped) Signup and view all the answers

What is the characteristic of iron atoms in a magnetic field?

They tend to align with the field, causing their electrons to move in an ordered way. Signup and view all the answers

What is the direction of the induced north pole in an iron filing in a magnetic field?

It points in the direction of the magnetic field at that point in space. Signup and view all the answers

Why do the iron filings shift their positions in the presence of a permanent magnet?

To line up with the magnetic field. Signup and view all the answers

What is the purpose of a soft core in an electromagnet?

To enhance the magnetic field produced by the coil. Signup and view all the answers

How does the number of turns in a coil affect the magnetic field produced by an electromagnet?

A coil with more turns causes a greater magnetic field. Signup and view all the answers

What is the difference between an electromagnet and a permanent magnet?

An electromagnet uses a current-carrying wire to create a magnetic field, while a permanent magnet has a permanent magnetic field. Signup and view all the answers

What is the pattern of iron filings used to demonstrate?

The magnetic field around a permanent magnet. Signup and view all the answers

What is the role of the current in an electromagnet?

To generate the magnetic field. Signup and view all the answers

What is the direction of the force acting on a particle moving in a magnetic field, and what is the resulting trajectory of the particle?

The force acts perpendicular to the magnetic field, and the resulting trajectory of the particle is a circle. Signup and view all the answers

Why is the speed of the particle unchanged as it moves in a magnetic field?

The speed of the particle is unchanged because the work done on the particle is equal to the change in kinetic energy, and no work is done. Signup and view all the answers

What is the formula for centripetal acceleration, and how is it related to the force required to create this acceleration?

The formula for centripetal acceleration is 𝑎𝑎 = 𝑣𝑣 2 / 𝑟𝑟, and the force required to create this acceleration is 𝐹𝐹 = 𝑚𝑚𝑎𝑎 = 𝑚𝑚𝑣𝑣 2 / 𝑟𝑟. Signup and view all the answers

What is the relationship between the radius of the circle, the speed of the particle, the mass of the particle, its charge, and the magnetic field strength?

The radius of the circle depends on the speed of the particle, the mass of the particle, its charge, and the magnetic field strength, and is given by 𝑟𝑟 = 𝑚𝑚𝑣𝑣 / 𝐵𝐵𝑞𝑞. Signup and view all the answers

Why is there no work done on the particle as it moves in a circular path?

There is no work done on the particle because the force is centripetal and the particle follows a circular path, resulting in no displacement in the direction of the force. Signup and view all the answers

What is the definition of work done on a particle, and how is it related to the change in kinetic energy?

Work done is defined as the product of the force and the displacement in the direction of the force, and is equal to the change in kinetic energy of the particle. Signup and view all the answers

What is the nature of the acceleration experienced by a particle moving in a magnetic field?

The acceleration experienced by a particle moving in a magnetic field is centripetal. Signup and view all the answers

What is the relationship between the magnetic field strength and the radius of the circle?

The magnetic field strength is inversely proportional to the radius of the circle, given by 𝑟𝑟 = 𝑚𝑚𝑣𝑣 / 𝐵𝐵𝑞𝑞. Signup and view all the answers

What is the purpose of a step-down transformer in a phone charger?

To lower the voltage supplied to the phone. Signup and view all the answers

What is the advantage of using an oscilloscope over a voltmeter when measuring the voltage across the input and output of a transformer?

An oscilloscope can more effectively measure the changing voltage. Signup and view all the answers

What is the purpose of a variable resistor (rheostat) in an experiment to investigate the efficiency of a transformer?

To vary the current at a constant voltage. Signup and view all the answers

How is the efficiency of a transformer estimated?

By calculating the ratio of output power to input power. Signup and view all the answers

What is the advantage of using laminated iron in the core of a transformer?

It reduces power loss to magnetic heating by reducing eddy currents. Signup and view all the answers

Why are soft iron cores more efficient in transformers?

They are easier to magnetize and demagnetize, and are more susceptible to changing magnetic fields. Signup and view all the answers

What is the purpose of using lower resistance wires in the coils of a transformer?

To reduce power loss to resistive heating. Signup and view all the answers

What is the formula to calculate the efficiency of a transformer?

η = (IpVp / IsVs) × 100%. Signup and view all the answers

What happens to the iron atoms in the iron core due to a changing magnetic field?

The iron atoms constantly align with the field Signup and view all the answers

What is the purpose of using step-up transformers in the transmission of electrical energy across the national grid?

To reduce power losses Signup and view all the answers

Why is the resistance of transmission lines often high despite being made of low resistivity metal and having a large cross-sectional area?

Because of the large distances between power stations and consumers Signup and view all the answers

What is the equation that relates power loss to current and resistance?

𝑃𝑃𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙 = 𝐼𝐼 2 𝑅𝑅 Signup and view all the answers

What is the purpose of step-down transformers in the transmission of electrical energy?

To decrease the voltage from the transmission cables Signup and view all the answers

Why do mobile phones require a lower voltage than the 230V mains supply?

Because some components may be sensitive to high voltages and technical faults may occur Signup and view all the answers

What is an example of a device that uses transformers in many homes?

A mobile phone charger Signup and view all the answers

What is the main application of transformers in the transmission of electrical energy?

To reduce power losses in transmission lines Signup and view all the answers