Nursery to 10th Class Questions & Answers

Percentage change tells you how much something increased or decreased compared to its original value. It is used in marks, prices, salary hikes, profit-loss, population, and basically everywhere numbers like to show off. Percentage Change Formula (Simplest Explanation) Percentage Change Formula Percentage Change (%) = [(New Value − Old Value) ÷ Old Value] × 100 How to Use the Formula (Step-by-Step) Step 1: Find the difference = New Value − Old Value Step 2: Divide the difference by the old value Step 3: Multiply the result by 100 How to Know if it is an Increase or a Decrease If New Value > Old Value , the answer is a percentage increase . If New Value < Old Value , the answer is a percentage decrease . If New Value = Old Value , the percentage change is 0% . Shortcut Version (Same Meaning) Percentage Increase (%) = [(Increase) ÷ (Original)] × 100 Percentage Decrease (%) = [(Decrease) ÷ (Original)] × 100 Important Notes (Small but Po...

A dicot leaf is the leaf of a dicotyledonous plant (a plant whose seed has two cotyledons). In simple words, many common plants around us, like hibiscus, mango, and rose, have dicot leaves. The easiest way to recognise it is to look at the veins. If the veins form a net-like pattern, it is usually a dicot leaf. Dicot Leaf with Examples How to Identify a Dicot Leaf Reticulate venation: The veins form a net (a network) instead of running parallel. Midrib is prominent: A main central vein is clearly visible, with many side veins branching out. Leaf is often broad: Many dicot leaves are wider, but shape can still vary a lot. Internal Structure (Useful for Biology Exams) Dorsiventral leaf: The upper and lower sides are not the same internally. Palisade mesophyll: Usually found towards the upper surface; it has more chloroplasts. Spongy mesophyll: Usually found towards the lower surface; it has more air spaces. Stomata: Often more on the lower surface in d...

Meaning: Centripetal force is the inward (center-seeking) net force that keeps an object moving in a circular path. No inward force = object goes straight along the tangent (Newton said "no curve without a cause"). Main Formula Fc = (m × v²) ÷ r What Each Symbol Means Fc = centripetal force (unit: Newton, N) m = mass (kg) v = speed along the circle (m/s) r = radius of the circular path (m) Why This Formula Works The centripetal acceleration in circular motion is: ac = v² ÷ r Using Newton's 2nd law F = m × a , we get: Fc = m × (v² ÷ r) So the final formula is: Fc = (m × v²) ÷ r Direction of Centripetal Force Centripetal force always acts toward the center of the circle. Velocity is tangential, but force is inward, so the object keeps turning instead of escaping like it has exam fear. Alternate Forms If you know angular speed (ω) instead of linear speed (v): v = ω × r ac = r × ω² Fc = m × r × ω² Quick Unit Check ...