The most important purpose of frog in a brick is to
- AEmboss manufacturer’s name
- BReduce the weight of the brick
- CForm keyed joint between brick and mortarCorrect
- DImprove insulation by providing ‘hollows’
Solution
Concept
Purpose of Frog in Bricks
Formula
No
Step-by-step solution
- Identify the frog as a depression on top of a brick - Note that mortar fills this depression to create a mechanical key between brick layers - Select option c
Explanation
The frog is a depression made on the top face of a brick that holds mortar, creating a mechanical key or lock between adjacent bricks to form a stronger bond.
Shortcut
Think of a "frog" as a webbed foot that grips—the frog in a brick grips the mortar to form a "keyed joint."
Common mistake
Many students mistakenly select Option A ("Emboss manufacturer’s name") because the brand or manufacturer's trade mark is commonly printed inside the frog. However, while it serves that secondary purpose, its primary structural function is to create a keyed joint for mortar to bind adjacent bricks together.
Correct answer: C) Form keyed joint between brick and mortar