An iron ring lies in a magnetic field as shown in the diagram. The field is uniformly increasing in magnitude. The induced current in the ring isScreen Shot 2021-07-29 at 3.16.27 PM.png 

How much current must pass through a 400-turn ideal solenoid that is 4.0 cm long to generate a 1.0-T magnetic field at the center? ( μ 0 = 4π × 10 -7 T ∙ m/A)

A simple ac circuit is composed of a capacitor connected across the terminals of an ac power source. If the frequency of the source is doubled, what happens to the reactance of the capacitor?

Which of the following statements is true for a series  RLC ac circuit in resonance? (There could be more than one correct choice).

An ideal parallel-plate capacitor has a capacitance of  C. If the area of the plates is doubled and the distance between the plates is halved, what is the new capacitance?

Three resistors with resistances of 2.0 Ω, 6.0 Ω, and 12 Ω are connected across an ideal dc voltage source  V as shown in the figure. If the total current through the circuit is  I = 2.0 A, what is the applied voltage  V?

A capacitor  C is connected in series with a resistor  R across a battery and an open switch. If a second capacitor of capacitance 2 C is connected in series with the first one, the time constant of the new  RC circuit will be

Calculate the Values of the currents I1 and I2 in the circuit shown. Screen Shot 2021-02-27 at 6.58.28 PM.png 

To achieve a homogeneous field with high image quality of a 1.5 – 3 T scanner a ppm of _________________ or less is required.

Which type of magnetism produces small negative effects to the external magnetic field?