An Object, Located 90 Cm from a Concave Lens, Forms

question 112

Multiple Choice

An object, located 90 cm from a concave lens, forms an image 30 cm from the lens on the same side as the object. What is the focal length of the lens?

• A) "-150 cm"
• B) "-45 cm"
• C) "-36 cm"
• D) "-180 cm"

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Definitions:

Pilot Device

An interface component used to control and monitor the operation of machinery or equipment, often initiating the start or stop commands.

Control Coil

The coil in a relay or contactor that, when energized, creates a magnetic field to pull in contacts, controlling circuit continuity.

Differential Switches

Devices designed to protect electrical circuits by automatically interrupting the current flow when detecting an imbalance between the incoming and outgoing current.

Pilot Devices

Controls, such as buttons and switches, used to operate machinery or equipment indirectly.