Guided course 09:10Current in a Circuit with a Changing Magnetic FieldPatrick Ford3574views58rank8comments
14:23Electromagnetic Induction (6 of 15) Faraday's Law, Example ProblemsStep by Step Science1046views
11:53Faraday's Law of Electromagnetic Induction, Magnetic Flux & Induced EMF - Physics & ElectromagnetismThe Organic Chemistry Tutor913views
Multiple ChoiceA tightly-wound 200-turn rectangular loop has dimensions of 40cm by 70cm. A constant magnetic field of 3.5T points in the same direction as the normal of the loop. If the dimensions of the loop change to 20cm by 35cm over 0.5s, with the number of turns remaining the same, what is the induced EMF on the rectangular loop?693views17rank5comments
Multiple ChoiceA square conducting wire of side length 4 cm is in a 2 T magnetic field. It rotates such that the angle of the magnetic field to the normal of the square increases from 30° to 60° in 2 s. What is the induced current on the wire if its resistance is 5 mΩ?620views11rank4comments
Multiple ChoiceThe figure shows a wire loop being moved toward a current-carrying wire. If the loop continues to move past the wire, so that the loop is lower than the wire in the picture, and still moving, what will be the direction of the induced current in the loop?550views1rank
Multiple ChoiceIn a region of space, a magnetic field is increasing at 3.0 T/s. A square loop of wire with a side of 12cm is oriented perpendicular to the field. The loop has a total resistance of 0.020 Ω. What current is induced in the loop?586views
Textbook QuestionA long, straight solenoid with a cross-sectional area of 8.00 cm^2 is wound with 90 turns of wire per centimeter, and the windings carry a current of 0.350 A. A second winding of 12 turns encircles the solenoid at its center. The current in the solenoid is turned off such that the magnetic field of the solenoid becomes zero in 0.0400 s. What is the average induced emf in the second winding?1261views1rank
Textbook QuestionThe magnetic field B at all points within the colored circle shown in Fig. E29.15 has an initial magnitude of 0.750 T. (The circle could represent approximately the space inside a long, thin solenoid.) The magnetic field is directed into the plane of the diagram and is decreasing at the rate of -0.0350 T/s. (e) If the ring is cut at some point and the ends are separated slightly, what will be the emf between the ends?286views
Textbook QuestionThe magnetic field B at all points within the colored circle shown in Fig. E29.15 has an initial magnitude of 0.750 T. (The circle could represent approximately the space inside a long, thin solenoid.) The magnetic field is directed into the plane of the diagram and is decreasing at the rate of -0.0350 T/s. (a) What is the shape of the field lines of the induced electric field shown in Fig. E29.15 , within the colored circle?274views
Textbook QuestionA long, thin solenoid has 400 turns per meter and radius 1.10 cm. The current in the solenoid is increasing at a uniform rate di/dt. The induced electric field at a point near the center of the solenoid and 3.50 cm from its axis is 8.00*10^-6 V/m. Calculate di/dt.893views1rank
Textbook QuestionA long, thin solenoid has 900 turns per meter and radius 2.50 cm. The current in the solenoid is increasing at a uniform rate of 36.0 A/s. What is the magnitude of the induced electric field at a point near the center of the solenoid and (a) 0.500 cm from the axis of the solenoid; (b) 1.00 cm from the axis of the solenoid?710views1rank
Textbook QuestionThe magnetic field within a long, straight solenoid with a circular cross section and radius R is increasing at a rate of dB/dt. (g) What is the magnitude of the induced emf if the radius in part (e) is 2R?538views
Textbook QuestionThe magnetic field within a long, straight solenoid with a circular cross section and radius R is increasing at a rate of dB/dt. (e) What is the magnitude of the induced emf in a circular turn of radius R/2 that has its center on the solenoid axis?441views
Textbook QuestionA metal ring 4.50 cm in diameter is placed between the north and south poles of large magnets with the plane of its area perpendicular to the magnetic field. These magnets produce an initial uniform field of 1.12 T between them but are gradually pulled apart, causing this field to remain uniform but decrease steadily at 0.250 T/s. (a) What is the magnitude of the electric field induced in the ring?712views1rank
Textbook QuestionThe conducting rod ab shown in Fig. E29.29 makes contact with metal rails ca and db. The apparatus is in a uniform magnetic field of 0.800 T, perpendicular to the plane of the figure. (b) In what direction does the current flow in the rod?512views
Textbook QuestionA flat, rectangular coil of dimensions l and w is pulled with uni-form speed v through a uniform magnetic field B with the plane of its area perpen-dicular to the field (Fig. E29.14). (a) Find the emf induced in this coil. (b) If the speed and magnetic field are both tripled, what is the induced emf?1062views
Textbook QuestionThe armature of a small generator consists of a flat, square coil with 120 turns and sides with a length of 1.60 cm. The coil rotates in a magnetic field of 0.0750 T. What is the angular speed of the coil if the maximum emf produced is 24.0 mV?473views
Textbook QuestionA closely wound rectangular coil of 80 turns has dimen-sions of 25.0 cm by 40.0 cm. The plane of the coil is rotated from a position where it makes an angle of 37.0° with a magnetic field of 1.70 T to a position perpendicular to the field. The rotation takes 0.0600 s. What is the average emf induced in the coil?1867views
Textbook QuestionShrinking Loop. A circular loop of flexible iron wire has an initial circumference of 165.0 cm, but its circumference is decreasing at a constant rate of 12.0 cm/s due to a tangential pull on the wire. The loop is in a constant, uniform magnetic field oriented perpendicular to the plane of the loop and with magnitude 0.500 T. (a) Find the emf induced in the loop at the instant when 9.0 s have passed.2516views2rank
Textbook QuestionA single loop of wire with an area of 0.0900 m^2 is in a uniform magnetic field that has an initial value of 3.80 T, is perpendicular to the plane of the loop, and is decreasing at a constant rate of 0.190 T/s. (a) What emf is induced in this loop?1476views
Textbook QuestionIn a physics laboratory experiment, a coil with 200 turns enclosing an area of 12 cm^2 is rotated in 0.040 s from a position where its plane is perpendicular to the earth's magnetic field to a position where its plane is parallel to the field. The earth's magnetic field at the lab location is 6.0*10-5 T. (b) What is the average emf induced in the coil?426views
Textbook QuestionThe magnetic field B at all points within the colored circle shown in Fig. E29.15 has an initial magnitude of 0.750 T. (The circle could represent approximately the space inside a long, thin solenoid.) The magnetic field is directed into the plane of the diagram and is decreasing at the rate of -0.0350 T/s. (d) What is the emf between points a and b on the ring?367views
Textbook QuestionFIGURE EX30.13 shows a 10-cm-diameter loop in three different magnetic fields. The loop's resistance is 0.20 Ω. For each, what are the size and direction of the induced current? a. b. c.473views
Textbook QuestionA 1000-turn coil of wire 1.0 cm in diameter is in a magnetic field that increases from 0.10 T to 0.30 T in 10 ms. The axis of the coil is parallel to the field. What is the emf of the coil?385views
Textbook QuestionCALC A 5.0-cm-diameter coil has 20 turns and a resistance of 0.50 Ω. A magnetic field perpendicular to the coil is B = 0.020t + 0.010t^2, where B is in tesla and t is in seconds. a. Find an expression for the induced current I(t) as a function of time.413views
Textbook QuestionCALC A 5.0-cm-diameter coil has 20 turns and a resistance of 0.50 Ω. A magnetic field perpendicular to the coil is B = 0.020t + 0.010t^2, where B is in tesla and t is in seconds. b. Evaluate I at t=5 s and t=10 s.33views
Textbook QuestionFIGURE P30.48 shows two 20-turn coils tightly wrapped on the same 2.0-cm-diameter cylinder with 1.0-mm-diameter wire. The current through coil 1 is shown in the graph. Determine the current in coil 2 at (a) t=0.05 s and (b) t=0.25 s. A positive current is into the figure at the top of a loop. Assume that the magnetic field of coil 1 passes entirely through coil 2.122views
Textbook QuestionA rocket zooms past the earth at v=2.0×10^6 m/s. Scientists on the rocket have created the electric and magnetic fields shown in FIGURE EX31.4. What are the fields measured by an earthbound scientist?30views
Textbook Question(I) The magnetic flux through a coil of wire containing two loops changes at a constant rate from -68 Wb to +48 Wb in 0.42 s. What is the emf induced in the coil?69views
Textbook Question(II) The area of an elastic circular loop decreases at a constant rate, dA/dt = -3.50 x 10⁻² m²/s. The loop is in a magnetic field B = 0.35 T whose direction is perpendicular to the plane of the loop. At t = 0, the loop has area A = 0.285 m². Determine the induced emf at t = 0, and at t = 2.00 s. 41views
Textbook Question(II) A circular wire loop of radius 𝓇 = 12 cm is in a uniform magnetic field B = 0.400 T with its plane perpendicular to the direction of the field. If the field magnitude begins to decrease at a rate of -0.010 T/s, at what rate should 𝓇 be increasing at this instant so that the induced emf within the loop is zero?47views
Textbook Question(II) A circular loop in the plane of the paper lies in a 0.65-T uniform magnetic field pointing into the paper. The loop’s diameter changes from 20.0 cm to 8.0 cm in 0.50 s. What is (a) the direction of the induced current, (b) the magnitude of the average induced emf, and (c) the average induced current if the coil resistance is 2.5Ω?43views
Textbook Question(II) A single circular loop of wire is placed inside a long solenoid with its plane perpendicular to the axis of the solenoid. The area of the loop is A₁ and that of the solenoid, which has n turns per unit length, is A₂. A current I = 1₀ cos ωt flows in the solenoid turns. What is the induced emf in the small loop?48views
Textbook Question(II) The magnetic field perpendicular to a single 13.2-cm-diameter circular loop of copper wire decreases uniformly from 0.760 T to zero. If the wire is 2.25 mm in diameter, how much charge moves past a point in the coil during this operation?56views
Textbook QuestionA circular loop of area 12 m² encloses a magnetic field perpendicular to the plane of the loop; its magnitude is B(t) = (8.0 T/s)t. The loop is connected to a 7.5-Ω resistor and a 6.5-pF capacitor in series. When fully charged, how much charge is stored on the capacitor?43views
Textbook QuestionWhat is the energy dissipated as a function of time in a circular loop of 18 turns of wire having a radius of 10.0 cm and a resistance of 2.0 Ω if the plane of the loop is perpendicular to a magnetic field given byB(t) = B₀e⁻ᵗ/ʳwith B₀ = 0.50 T and τ = 0.10 s?25views
Textbook QuestionMagnetic flux passes through a stationary loop of wire with resistance R and this flux varies from t = 0, to t = T/2 such that Φ(t) = b sin(2𝝅t/T) where b is a given constant. Estimate the energy dissipated in the loop during that time.40views
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