CBSE Class 9 - Science - Floatation 7 Simple Numerical You Must Know

Floatation
7 Simple Numerical You Must Know

Q1: A force of 200 N acts on a surface of area 10 cm². Calculate thrust and pressure. How much the pressure changes if the area of contact increases to 50 cm².

Answer:
Force = 200 N
Area = 10cm² = 10 x 10^-4m²
Pressure (P) = Force ÷ Area
P1 = 200 ÷ 10 x 10^-4 = 2 x 10⁵ Pa

New area = 50cm² = 50 x 10^-4m²
P2 = 200 ÷ 50 x 10^-4 = 4 x 10⁴ Pa

Change in Pressure = P1 - P2 = 2 x 10⁵   - 4 x 10⁴
                                = 1.6 x 10⁵ Pa



Q2: A cuboid room has dimensions 50m x 15m x 3.5m. What is the mass of the air enclosed in the room if the density of air = 1.30 kg/m³.


Answer: Volume of room (V) = 50m x 15m x 3.5m = 2625m³
Density of air (d) = 1.30 kg/m³
Mass of air = V x d = 2625 x 1.30 = 3412.5 kg

Class 10 - Biology - How Do Organisms Reproduce? - Worksheet

Reproduction 

Longitudinal Section of a Bisexual Flower
Label the parts of the flowers (answer given in this post)
image credits: wikimedia

Worksheet

Fill in the blanks


1. In _________, many bacteria and protozoa simply divide into two or more daughter cells.


2. __________ is associated with the stability of population of species.


3. The fertilized egg gets implanted in the lining of the ________.


4. In mammals, the embryo gets nutrition from the mother’s blood with the help of a special tissue called _________.

Class 9 - Maths - Quadrilaterals - Important Points to remember (#CBSE-Notes)

Quadrilaterals 

Important Points to remember

Based on Class 9 NCERT Chapter on Quadrilaterals

Simple Classification of Quadrilaterals.
For detailed version check at wikipedia

① A simple closed figure bounded by four line segments is called quadrilateral.

② The sum of (interior) angles of a quadrilateral is 360°- Angle Sum Property of Quadrilateral

③ A quadrilateral in which one pair of opposite sides is parallel is called trapezium.

④ A quadrilateral in which both pairs of opposite sides are parallel is called parallelogram.

⑤ If one of the angles of a parallelogram is right angle then it is a rectangle.

⑥ If all sides of a quadrilateral are equal then it is called rhombus.

CBSE Class 11/ Class 12/ NEET - Biology - Kingdom Fungi (MCQs)

Kingdom Fungi 

Fungus, Mushroom
credits: Copyright Pam Brophy

MCQs for AIPMT, PreMedical, NEET


Q1: Black rust of wheat is caused by ________

(a) Puccinia
(b) Mucor
(c) Aspergillus
(d) Rhizopus


Q2: Adhesive pad of fungi enters into the host with the help of

(a) mechanical pressure and enzymes
(b) hooks and suckers
(c) softening by enzymes
(d) only by mechanical pressure


Q3: Which fungal disease spreads by seed and flowers?

(a) Corn stunt
(b) Loose smut of wheat
(c) Covered smut of barely
(d) Soft rot of potato


Q4: Zygospores are formed in

(a) Puccinia
(b) Penicillium
(c) Alternaria
(d) Rhizopus.

Class 8 Our Pasts - Chapter 5 - When People Rebel- 1857 and After (Worksheet)

When People Rebel- 1857 and After

Worksheet based on NCERT Class 8 Our Pasts Chapter 5   

Rani Laxmi Bai - Statue
(image credits: Wikimedia)
Read Poem

Worksheet

Fill in the blanks.

1. When soldiers as a group disobey their officers in the army, it is called ___________.


2. In 1849, Governor-General announced that after the death of ______________, the family of the king would be shifted out of the Red Fort and given another place in Delhi to reside in.


3. In 1856, Governor-General _________ decided that Bahadur Shah Zafar would be the last Mughal king.


4. Subedar Sitaram, a sepoy in the Bengal Native Army, served the English for 48 years and retired in 1860. He published his memoirs under the title _______________.

CBSE Class 9 - Science - CH 13 - Why Do We Fall iLL? (Important Differences)

Why Do We Fall iLL?

 (Important Differences)

Q1: Write three differences between Personal Health and Community Health.

Answer:

Personal Health	Community Health
1. It is a state of physical, mental and social well being.	1. It refers to maintenance, improvement of public health or environmental health.
2. It focuses on individual's health.	2. Its focus is on community health.
3. Objectives are achieved by individual by observing personal and domestic hygiene.	3. Objectives are fulfilled by providing safe water, medical facilities, proper sewage disposal etc.

Q2: What are the important differences between symptoms and signs?

Answer: Please see answer in the previous post Q12.



Q3: Write differences between 'Being Healthy' and 'Disease Free'.

Answer:

CBSE Class 9/10/11/12 - English Vocabulary - One Word Substitution

One Word Substitution

One word, representing a phrase or sentence or clause, helps in communicating precisely. Here is a list of 20 commonly used words. You may also check this quiz on One word Substitution to learn 100+ words.


1. Able to use the left hand and right hand equally well - Ambidextrous

2. A lightly constructed open booth generally used as a newsstand- Kiosk

3. A game in which in which no one wins - Draw

4. A sweet music - Melody

5. An official call to appear in a court of law - Summon

6. Words of similar meaning - Synonyms

7. Belonging to all parts of the world - Universal