Question

In Auto Cad when a layer is turned off

• A. Details can still be added to the layer
• B. Details on the layer cannot be seen
• C. Details cannot be erased from the layer
• D. Design file is displayed % This is too general and unrelated to layer state.

Hint:

\textbf{Layer Turned OFF:}
Objects on the layer become invisible.
Objects are not plotted.
Objects still exist in the drawing database and are regenerated.
You cannot draw on or directly edit objects on an OFF layer.
\textbf{Layer Frozen:}
Objects are invisible and not plotted.
Objects are NOT regenerated, which can improve performance.
You cannot draw on or edit objects on a frozen layer.
Turning a layer OFF makes its contents invisible.

Answer 1

The Correct Option is B

In AutoCAD (and other CAD software), layers are used to organize and manage different parts of a drawing. Each layer can have properties like color, linetype, lineweight, and visibility states. Common visibility states for a layer:
On/Off:
On: Objects on the layer are visible and can be plotted (printed).
Off: Objects on the layer are invisible (cannot be seen on the screen) and are not plotted. However, objects on a layer that is turned OFF are still part of the drawing database and are regenerated with the drawing. You cannot directly select or modify objects on an OFF layer, but they exist.
Freeze/Thaw:
Thawed (Unfrozen): Similar to "On," objects are visible and plottable.
Frozen: Objects on a frozen layer are invisible, not plotted, and, importantly, are not regenerated by AutoCAD during operations like zoom, pan, or regen. This can improve performance in very large drawings. You cannot add or modify objects on a frozen layer.
Lock/Unlock:
Locked: Objects on a locked layer are visible but cannot be selected or edited (prevents accidental modification).
Unlocked: Objects are visible and editable. The question asks what happens when a layer is "turned off". When a layer is turned OFF:
Details on the layer cannot be seen (they become invisible). This matches option (b).
You generally cannot add new details (objects) to a layer that is turned OFF because you cannot make it the current layer if it's off, or selection/snapping to existing entities on it is impossible. (So (a) is incorrect).
You cannot erase details from an OFF layer because you cannot select them. You'd need to turn the layer ON to select and erase. (So (c) "Details cannot be erased" is true in the sense you can't interact, but the objects still exist and can be erased if layer is turned on).
(d) "Design file is displayed" is irrelevant to the state of a single layer. The most direct and primary consequence of turning a layer OFF is that its contents become invisible. \[ \boxed{\text{Details on the layer cannot be seen}} \]