Physics Electromagnetic Induction Level: High School
An aluminum ring of radius 5.00 cm and resistance 3.00 x 10^-4 ohms is placed around the top of a long air-core solenoid with 1000 turns per meter and a smaller radius of 3.00 cm . If the current in the solenoid is increased at a constant rate of 270 A/s . what is the induced current in the ring ? Assume that the magnetic field produced by the solenoid over the area at the end of the solenoid is one-half as strong as the field at the center of the solenoid . Assume also that the solenoid produces a negligible field outside its cross-sectional area .
Physics Alternating Current Level: High School
Alternating Currents
A resistor with a resistance of 500 ohm and a capacitor with a capacitance of 2.00 micro F are connected in parallel to an ac generator that supplies a rms voltage of 240 V at an angular frequency of 377 rad . s-1 . Finda) The current amplitude in the resistor .
b) The current amplitude in the capacitor
c) The phase angle (sketch the phasor diagram for the current phasors)
d) The amplitude of the current through the generator .
Physics Electromagnetic Induction Level: High School
Inductance
A toroidal solenoid has two coils with N1 and N2 turns , both wound in the same direction . The solenoid has radius r and cross sectional area A .a) Derive an expression for the self-inductance L1 when only the first coil is used and an expression for L2 when only the second coil is used .
b) Derive an expression for the mutual inductance of the two coil .
c) Show that M2 = L1 L2 . This result is valid whenever all the flux linked by one coil is also linked by the other .
Physics Electromagnetic Induction Level: High School
Electromagnetic Induction
A solenoid 0.500 m long and 0.0800 m in diameter is wound with 500 turns. A closely wound coil of 20 turns of insulated wire surrounds the solenoid at its midpoint, and the terminals of the coil are connected to a charge-measuring instrument. The total current resistance is 40.0 ohm .a) Find the quantity of charge displaced through the instrument when the current in the solenoid is quickly decreased from 3.00 A to 1.00 A .
b) Draw a sketch of the apparatus , showing clearly the directions of the windings of the solenoids and coil and of the current in the solenoid . Show on your sketch the direction of current in the coil when the solenoid current is decreased .
Physics Magnetism,Magnetic Effects Of Current Level: High School
Magnetic field and Magnetic Force
An electron and a alpha particle (a doubly ionized helium atom) both move in a magnetic field in circular paths with the same tangential speed . Compute the ratio of the number of revolutions the electron makes per second to the number made per second by the alpha particle is 6.68 x 10^-27 kg
Physics Electromagnetic Induction Level: High School
a) What is the inductive time constant of the circuit.
b) Calculate the current in the circuit 250 us after the switch is closed
c) What is the value of the final steady-state current
d) How long does it take the current to reach 80.0% of its maximum value ?
Physics Electromagnetic Induction Level: High School
A circular coil enclosing an area of 100 cm squared is made of 200 turns of copper wire . The wire making up the coil has resistance of 5.0 ohms and the ends of the wire are connected to a form closed circuit . Initially , a 1.1 T uniform magnetic field points perpendicularly upward through the place of the coil . If the time required for the field to reverse directions is 0.10 s , what average current flows through the coil during that time ?
Physics Magnetism,Magnetic Effects Of Current Level: High School
A lightning bolt may carry a current of 1.00 x 10 to the 4th power Amps for a short time . What is the resulting magnetic field 100 m from the bolt ? Suppose that the bolt extends far above and below the point of observation .
Physics Magnetism,Magnetic Effects Of Current Level: High School
An eight turn coil encloses an elliptical area having a major axis of 40 cm and a minor axis of 30 cm . (The elliptical area is 40 cm high and 30 cm wide on the page). The coile lies in the plane of the page and has a 6.00 Amp current flowing clockwise around it. If the coil is in a uniform magnetic field of 2.00 x 10 to the -4 T directed to the left of the page , what is the magnitude of the torque in the coil ?
Physics Magnetism,Magnetic Effects Of Current Level: High School
A 15 Amp current is detected along the positive X axis and perpendicular to a magnetic field . A magnetic force per unit length of 0.12 N/m acts on the conductor in the negative y direction. Calculate the magnitude and direction of the magnetic field in the region in which the current passes .
Physics Magnetism,Magnetic Effects Of Current Level: High School
How many ampere-turns are there in one gilbert ?a)
b) 1.257
c) 10^4
d) 10^8
Physics Magnetism,Magnetic Effects Of Current Level: High School
What are the mks unit and magnitude of 12.57 Oe ?a) 1 At/m
b) 1 at
c) 10 At/m
d) 10 At
e) 100 At/m
f) 100 At
g) 1000 At/m
h) 1000 At
Physics Magnetism,Magnetic Effects Of Current Level: High School
What are the mks unit and magnitude of 25 gilberts ?a) 0.032 At/m
b) 20 At/m
c) 0.032 At
d) 20 At
Physics Magnetism,Magnetic Effects Of Current Level: High School
What is the length of the coil , assuming an average diameter of the turns is equal to 3.5 inches ?a) 1286 ft .
b) 125 ft.
c) 784 ft.
d) 916 ft.
Physics Magnetism,Magnetic Effects Of Current Level: High School
The magnetic characteristics of a core material are shown in the figure at “click here”. What change in magnetizing force is required to reserve the direction of the magnetic field from saturation in the positive direction to saturation in the negative direction ?a) 110 At/m
b) 140 At/m
c) 180 At/m
d) 220 At/m
