Velocity Selector: the Figure Shows a Velocity Selector That Can

question 67

Multiple Choice

Velocity selector: The figure shows a velocity selector that can be used to measure the speed of a charged particle. A beam of particles is directed along the axis of the instrument. A parallel plate capacitor sets up an electric field E, which is oriented perpendicular to a uniform magnetic field B. If the plates are separated by 2.0 mm and the value of the magnetic field is 0.60 T, what voltage between the plates will allow particles of speed 5.0 × 10⁵ m/s to pass straight through without deflection?

• A) 600 V
• B) 1900 V
• C) 3800 V
• D) 190 V
• E) 94 V

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Definitions:

Rods

Photoreceptor cells in the retina of the eye that are sensitive to low light levels and are crucial for night vision.

Visual System

The part of the central nervous system which enables organisms to process visual detail, and includes the eye, the optic nerves, and the brain's visual cortex.

Rods

Photoreceptor cells in the retina of the eye that are responsible for vision at low light levels but do not mediate color vision.

Peripheral Vision

The part of vision that occurs outside the very center of gaze, allowing humans to perceive objects and movements at the edges of their visual field.