A convex lens makes light rays converge (come together) at the focal point or focus. The distance from the center of the lens to the focal point is the focal length of the lens. Convex lenses are used in things like telescopes and binoculars to bring distant light rays to a focus in your eyes.

3 0

4 years ago

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When the current in a toroidal solenoid is changing at a rate of 0.0275 a/s, the magnitude of the induced emf is 12.4 mv. when t

slavikrds [6]

Answer:

41 turns

Explanation:

$\dfrac{d\phi}{dt}$ = Induced emf = 12.4 mV

$\dfrac{dI}{dt}$ = Current changing rate = 0.0275 A/s

L= Inductance

$\phi$ = Average flux = 0.00285 wb

N = Number of turns

Change in flux is given by

$\dfrac{d\phi}{dt}=L\dfrac{dI}{dt}\\\Rightarrow 12.4\times 10^{-3}=L0.0275\\\Rightarrow L=\dfrac{2.4\times 10^{-3}}{0.0275}\\\Rightarrow L=0.08727\ H$

Flux through each turn is given by

$\dfrac{\phi}{N}=L\dfrac{I}{N}\\\Rightarrow 0.00285=0.08727\times \dfrac{1.34}{N}\\\Rightarrow N=\dfrac{0.08727\times 1.34}{0.00285}\\\Rightarrow N=41.03221\ turns$

The number of turns is 41

3 0

3 years ago

Which of the following lead-acid battery voltages has the highest value? A. Floating voltage B. Discharge voltage c. Open-circui

MissTica

Answer:

option D

Explanation:

the correct Answer is option D

From the given options Equalize voltage lead acid battery has the highest value.

most of the electric circuits are connected with the ground which means circuit is connected to earth surface. The ground is said to be floating when this connection does not exist.

discharge voltage is the voltage which is at the end of the circuit.

open circuit voltage is the difference between the electric potential between the two terminals.

8 0

4 years ago