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3 years ago

Define the focus of a concave lens

Physics

1 answer:

Sophie [7]3 years ago

8 0

Answer:

Principal focus of concave lens - 

★ The point at which rays parallel to principal axis coming from infinity appear to converge after being refracted from concave lens is called the principal focus of concave lens.

________________________

• Additional information - 

★ Principal focus - A number of rays parallel to the principal axis after reflection from a concave mirror meet at a point on the principal axis or appear to come from a point after reflection from a convex mirror on the principal axis. This is called principal focus.

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A 0.130 m radius, 485-turn coil is rotated one-fourth of a revolution in 4.17 ms, originally having its plane perpendicular to a

Lady_Fox [76]

Answer:

The magnetic field strength needed is 1.619 T

Explanation:

Given;

Number of turns, N = 485-turn

Radius of coil, r = 0.130 m

time of revolution, t = 4.17 ms = 0.00417 s

average induced emf, V = 10,000 V.

Average induced emf is given as;

V = -ΔФ/Δt

where;

ΔФ is change in flux

Δt is change in time

ΔФ $= -NBA(Cos \theta_f - Cos \theta_i)$

where;

N is the number of turns

B is the magnetic field strength

A is the area of the coil = πr²

θ is the angle of inclination of the coil and the magnetic field,

$\theta_f = 90^o\\\theta_i = 0^o$

V = NBACos0/t

V = NBA/t

B = (Vt)/NA

B = (10,000 x 0.00417) / (485 x π x 0.13²)

B =1.619 T

Thus, the magnetic field strength needed is 1.619 T

5 0

3 years ago

Read 2 more answers

A blue box and green box are sitting on a table not moving. A student exerts the same force on both boxes and observes how long

dem82 [27]

Answer:

2 possible answers. 1. The green box is heavier. or 2nd. The green box has bigger friction than blue box.

Those should be the 2 main explanations. There probably are other options

5 0

3 years ago

Read 2 more answers

ONLY TWO ANSWER CHOICES!!

Otrada [13]

A: Buoyant force is equal to the weight

3 0

3 years ago

What is the acceleration of a proton moving with a speed of 6.5 m/s at right angles to a magnetic field of 1.5 T?

Brilliant_brown [7]

Answer:

The acceleration of the proton is 9.353 x 10⁸ m/s²

Explanation:

Given;

speed of the proton, u = 6.5 m/s

magnetic field strength, B = 1.5 T

The force of the proton is given by;

F = ma = qvB(sin90°)

ma = qvB

where;

m is mass of the proton, = 1.67 x 10⁻²⁷ kg

charge of the proton, q = 1.602 x 10⁻¹⁹ C

The acceleration of the proton is given by;

$a = \frac{qvB}{m}\\\\a = \frac{(1.602*10^{-19})(6.5)(1.5)}{1.67*10^{-27}}\\\\a = 9.353*10^8 \ m/s^2$

Therefore, the acceleration of the proton is 9.353 x 10⁸ m/s²

4 0

3 years ago

How are base units and derived units related?

Vlad1618 [11]

Answer:

SI derived units

Other quantities, called derived quantities, are defined in terms of the seven base quantities via a system of quantity equations. The SI derived units for these derived quantities are obtained from these equations and the seven SI base units.

Explanation:

Hope this helps :D

8 0

3 years ago

Define the focus of a concave lens ​

Define the focus of a concave lens