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Can a charged object be made to attract another object of the same charge?
A small plastic rod is rubbed with a cloth, resulting in the transfer of electrons. The rod then attracts a small piece of paper, but not a second identical plastic rod. Analyze the phenomenon and explain the underlying principle.
Electrostatic Shielding of a Charged Object?
A small charged object of 10 cm radius is placed inside a hollow metal sphere of 20 cm radius. What happens to the electric field and potential outside the sphere when the object is brought near the center of the sphere, and how does it affect the capacitance of the sphere?
Motion of a Charged Particle?
A charged particle moves along a uniform electric field. If the electric field is increased by a factor of 4, how will the path of the particle change? Explain with a neat diagram and support your answer with relevant concepts from the chapter.
How does the Electric Field affect the trajectory of charged particles?
A charged particle of mass 1 kg and charge 2 μC is projected into a uniform electric field of 4 × 10^4 N/C. If the particle is projected at an angle of 60° with the direction of the electric field, what will be its trajectory and how will it change if the charge is doubled?
How does the presence of a moving conductor affect the magnetic field strength?
A straight copper wire of length 2 m is moving with a constant velocity of 10 m/s in a direction perpendicular to a magnetic field of 0.5 T. What happens to the magnetic field strength when the wire is moving in the same direction as the magnetic field? In a different direction? Assume the wire's cross-sectional area is negligible.
Magnetic Field Lines and Matter Interaction?
A rare-earth magnet is placed near a paper clip. Describe the changes in the magnetic field lines and their interactions with the paper clip, assuming the magnet's strength remains constant.
Capacitor in Parallel: How does it affect the Total Capacitance?
Three capacitors of 10 μF, 20 μF, and 30 μF are connected in parallel across a 200 V supply. What is the total capacitance of the combination and how does it compare with the capacitance of each individual capacitor?
Why does a long straight wire carry current produce a magnetic field?
A current-carrying long straight wire is placed parallel to a cylindrical conductor made of a non-ferromagnetic material. The wire carries a current of 5 A, and the cylinder has a radius of 0.5 m. Explain how the direction of the magnetic field produced by the wire can be determined using the right-hand rule in different situations – when the wire and cylinder are stationary, and when the wire is moving past the cylinder while the cylinder is stationary.
Lifting a Lift Off?
A DC motor is used to power a lift in an amusement park, and suddenly the power supply is interrupted due to a short circuit. Explain the effect on the current flowing through the motor and the lift's motion.
Induced Voltage in Alternating Fields?
A conductor is placed in an alternating magnetic field of frequency 50 Hz. Explain, with suitable mathematical reasoning, how the induced voltage in the conductor changes with time, assuming the magnetic field's amplitude remains constant.
Magnetic Field and Lenz's Law Inversion?
A superconducting material, when cooled, exhibits perfect diamagnetism. You are given a long solenoid with its axis aligned with the radius of a superconducting ring. When the current in the solenoid is switched on, devise a method to induce a current in the superconducting ring using the principle of electromagnetic induction.
Kirchhoff's Loop Rule Conundrum?
In a circuit containing a 2 Ω resistor, a 3 V battery, and an unknown inductor, the total resistance is measured to be 5 Ω. Using only Kirchhoff's loop rule, derive an expression for the inductance of the inductor and discuss its implications on the circuit.
Induced EMF in a Rotating Coil?
A coil of radius 20 cm, with 100 turns, rotates about its diameter in a uniform magnetic field of 0.2 T. If the coil makes 50 revolutions in 20 seconds, what is the average induced EMF in the coil?
Magnetic Field of a Solenoid?
A current of 2 A flows through a solenoid of 100 turns and length 0.1 m. If the magnetic field inside the solenoid is 100 μT, what is the magnetic moment of the solenoid? Assume the current is switched off and then the solenoid is used as a magnet. How would the magnetic moment change if the number of turns is doubled and the length is halved?
Motion of Charged Particles in Electric Fields?
A uniform electric field of 2 × 10^4 N/C is directed along the positive x-axis. A particle with charge 6 × 10^-8 C is moving in this field with an initial velocity of 2 × 10^5 m/s. If the particle is released from rest at a distance of 1 m from the point where the electric field is measured, what will be its speed when it reaches the point of release?
Effect of Temperature on Resistivity?
The resistivity of a conductor increases with an increase in temperature. However, a certain metal shows a decrease in resistivity with an increase in temperature. What could be the reason for this anomaly and how would you verify it experimentally?
Induction in Multiple Coils?
Suppose you have a coil of wire connected to a galvanometer and placed near a second coil with a varying magnetic field. If the first coil is moved closer to the second coil, how does the magnitude of the induced current in the galvanometer change? Explain, considering the effects of the changing magnetic flux and the number of turns in the coils.
Can Electromagnetic Induction be Reversed?
A transformer is connected to a power source, and a magnet is placed near the coil. If the magnet is removed, but the power source remains, will the induced voltage in the coil increase, decrease, or remain the same?
Electric Power in a Circuit?
In a circuit consisting of a 500 Ω resistor connected to a 10 V battery with an internal resistance of 5 Ω, calculate the total power dissipated across the circuit terminals when a current of 0.1 A flows through the circuit.
Magnetic Field and Electric Current Interaction?
A straight wire of length 2 meters carries a current of 5 A. It is placed perpendicular to a uniform magnetic field of strength 0.3 T. The wire is then bent into a semicircle of radius 0.5 meters. How does the magnetic field strength required to produce a force of 50 mN on the wire affect the length of the wire?
Lenz's Law In Action?
A coil of wire is placed near a bar magnet and connected to a galvanometer. As the magnet is moved towards the coil, the galvanometer shows a deflection. Explain, with the help of Lenz's law, why the direction of this deflection is as observed.
Quantitative Nature of Electric Charges?
Consider two identical conducting spheres, one charged positively and the other negatively, but with the same magnitude of charge. How do the electric charge distribution and field lines on the surface of these spheres compare, assuming they are isolated in space?
Electric Shielding: A Conundrum
A thin layer of conducting material, such as a sheet of copper, is placed between a point charge and a free charge. What effect will the shielding have on the free charge if it is (i) positive and (ii) negative, respectively?
Magnetic Field of a Solenoid
A long solenoid with 200 turns per meter and a current of 5 A is placed near a compass. The compass needle shows deflection. Assuming the Earth's magnetic field is negligible, determine the direction of the magnetic field at the compass and the number of turns per meter required to produce a magnetic field of 0.5 T at the compass, given the current is doubled to 10 A.
Magnetic Field Around a Coil?
A current-carrying coil of 50 turns is placed in a horizontal plane. The current flowing through the coil is 2A. At a distance of 10cm from the coil's center, a magnetic field of 5 x 10^-6 T is measured using a magnetometer. How will the magnetic field strength change if the number of turns in the coil is doubled, while keeping the current and distance constant?
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