The flow of Direct current (DC) is constant and flows in one direction. Most digital electronics make use of DC. Alternating current (AC) periodically flows in reverse and is mostly used to deliver power to houses, buildings and the like. With that alone, you can already rule out A, C and D.
The answer would then be B. constant, periodically reversing.
Answer: The ray that passes through the focal point on the way to the lens will refract and travel parallel to the principal axis. ... All three rays should intersect at exactly the same point.
Explanation: Once these incident rays strike the lens, refract them according to the three rules of refraction for converging lenses.
Answer:
The voltage across the capacitor is 1.57 V.
Explanation:
Given that,
Number of turns = 10
Diameter = 1.0 cm
Resistance = 0.50 Ω
Capacitor = 1.0μ F
Magnetic field = 1.0 mT
We need to calculate the flux
Using formula of flux
Put the value into the formula
We need to calculate the induced emf
Using formula of induced emf
Put the value into the formula
Put the value of emf from ohm's law
We know that,
We need to calculate the voltage across the capacitor
Using formula of charge
Put the value into the formula
Hence, The voltage across the capacitor is 1.57 V.
Answer:
Approximately (approximately ) assuming that the magnetic field and the wire are both horizontal.
Explanation:
Let denote the angle between the wire and the magnetic field.
Let denote the magnitude of the magnetic field.
Let denote the length of the wire.
Let denote the current in this wire.
The magnetic force on the wire would be:
.
Because of the term, the magnetic force on the wire is maximized when the wire is perpendicular to the magnetic field (such that the angle between them is .)
In this question:
- (or, equivalently, radians, if the calculator is in radian mode.)
- .
- .
- .
Rearrange the equation to find an expression for , the current in this wire.
.