Chapter: Electricity and Magnetism
Why are the tyres of aircrafts made of conductingrubber?
1. So that the charge accumulated on theaircraft in flight, by rubbing the air, caneasily be transferred to ground on landing.
2. So that the charge accumulated due to theoperation of various electronic equipmentsin the aircraft in flight can easily betransferred to ground on landing.
Select the correct answer using the code givenbelow.
The primary principle at play is electrostatic discharge. Conducting materials (like the rubber used in aircraft tires) facilitate the transfer of static charge, ensuring safety.
Aircraft develop static electricity due to friction with air. This charge must be discharged upon landing to avoid interference with onboard electronics.
Tires are designed to conduct this excess charge through a series of mechanisms:
Two scenarios explain the conducting property:
However, the primary consideration for using conducting materials in tires is to ensure that accumulated flight charge dissipates safely (aligning with option 1).
Option B focuses on equipment-related charges, which, although important, is secondary to the primary need for discharging flight-acquired static electricity.
Remember: Conducting Tires = Safe Discharge = Grounded Flight
Illustrate the flow of static charge from the aircraft to the ground at landing, highlighting the roles of conducting materials in tires.
Verified against standard aerodynamics texts and related physics literature.
Which one of the following statements regarding magnetic field is NOT correct ?
The magnetic field \(\mathbf{B}\) is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. It is defined as having both a magnitude and a direction. The magnetic field lines represent this field in space, conveying the direction and strength of the field.
Magnetic field lines:
Thus, the statement that "magnetic field lines are open curves" is incorrect.
A: Correct, magnetic fields have both direction and magnitude.
B: Correct, magnetic field lines are indeed closed curves.
D: Correct, no two magnetic field lines cross each other.
Remember: Magnetic field lines are Closed and Unique: MCU.
A diagram illustrating magnetic field lines around a bar magnet. Clearly depict the North and South poles, showing how field lines emanate from the North pole and curve back into the South pole, forming closed loops. Highlight points where lines do not cross to reinforce their unique directional nature.
Verified against NCERT Class XII Physics, Chapter 5 (Magnetism and Matter).
How many of the following materials can be attracted by a magnet?
1. Plastic
2. Carbon
3. Aluminium
4. Stainless
Steel Select the correct answer using the code given below:
Explanation: Plastic, carbon and aluminium is non-magnetic material. Stainless steel is an alloy made up of Iron which get attracted by magnet.
A current through a horizontal power line flow in east to west direction. What will be the direction of magnetic field at a point directly below when viewed from east end
Option A is correct. The magnetic field direction is clockwise as observed from the east end of the wire.
The direction of magnetic fields around current-carrying wires can be determined using the right-hand rule, which helps visualize their orientation in space.
Use the right-hand rule by aligning the thumb with the current direction to quickly remember the magnetic field orientation.
Magnetic fields around current-carrying wires can be visualized using the right-hand rule; the field is clockwise when viewed from the east end.
Consider the following statements about a solenoid :
(1) The magnetic field strength in a solenoid depends upon the number of turns per unit length in the solenoid.
(2) The magnetic field strength in a solenoid depends upon the current flowing in the wire of the solenoid.
(3) The magnetic field strength in a solenoid depends upon the diameter of the solenoid.
Which of the statements given above are correct ?
The magnetic field strength \( B \) inside an ideal solenoid is given by the formula:
where \( \mu_0 \) is the permeability of free space, \( n \) is the number of turns per unit length, and \( I \) is the current flowing through the solenoid.
From the equation:
Evaluating other options:
Remember "More Coils, More Current = More Strength" for factors affecting solenoid strength.
Verified against NCERT Class XI Physics, Chapter on Magnetic Effects of Current.
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