Showing posts with label class10-physics. Show all posts
Showing posts with label class10-physics. Show all posts

Wednesday 3 January 2018

CBSE Class 10 - Physics - The Human Eye and the Colourful World – Unit Test Paper (#eduvictors)(#cbsepapers)

The Human Eye and the Colourful World – Unit Test Paper

CBSE Class 10 - Physics - The Human Eye and the Colourful World – Unit Test Paper (#eduvictors)(#cbsepapers)

Q1: A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power which type?

Q2: Give reasons for the following:
i. Stars twinkle at night.
ii. The sun appears reddish early in morning.
iii. Planets do not twinkle.
iv. Red colour is used in danger signals.

Q3: A person walking in desert gets a illusion of seeing water. Name the phenomenon of light responsible for it.

Q4: Distinguish between Refraction and Dispersion.

Tuesday 2 January 2018

CBSE CLASS 10 - Physics - Refraction From Lens - Worksheet (#cbseNotes)(#eduvictors)

Physics - Refraction From Lens

CBSE CLASS 10 - Physics - Refraction From Lens - Worksheet (#cbseNotes)(#eduvictors)


Q1: In refraction of light, what does Snell's Law state?

Answer: The ratio of sine of angle of incidence to the sine of angle of refraction remains constant subject to certain conditions. This is called refraction.


Q2: Which of the following property of light wave changes when it travels from one medium to another (having different optical densities)?

a. Wavelength
b. Speed of Light
c. Frequency

Tuesday 7 November 2017

CBSE Class 10 - Physics - Human Eye and Colourful World - What is Total Internal Reflection? (#eduvictors) (#cbseNotes)

What is Total Internal Reflection?

CBSE Class 10 - Physics - Human Eye and Colourful World - What is Total Internal Reflection? (#eduvictors) (#cbseNotes)

① When a ray of light travels from optically denser medium to optically rarer medium, it bends away from the normal at the surface separating two media.

Sunday 5 November 2017

CBSE Class 8 Science – Light, Refraction and Dispersion - Assignment (#cbseNotes) (#eduvictors)

CBSE Class 8 Science – Light, Refraction and Dispersion - Assignment (#cbseNotes) (#eduvictors)

Science – Light, Refraction and Dispersion - Assignment


Q1: What do you mean by refraction of light? In which direction will light bend when travelling from an optically rarer medium to an optically denser medium?

Q2: Name the part of the eye which gives colour to the eyes.

Q3: Boojho while waving his hand very fast in front of his eyes, observes that his fingers appear blurred. What could be the reason for it?

Q4: How many times is a ray of light reflected by two plane mirrors placed parallel and facing each other?

Saturday 9 September 2017

Class 10 - Physics - Light and Reflection - Magnification Chart For Mirrors (#cbseNotes)

Light and Reflection -
Magnification Chart For Mirrors

Class 10 - Physics - Light and Reflection - Magnification Chart For Mirrors (#cbseNotes)


Q: What is Magnification?

Answer: The ratio of height of image to the height of an object is known as magnification of an image and is denoted as m.

           Image height         h'     -v
    m = -------------------- = ---- = ----
           Object height        h       u
 


The +ve value of magnification represents virtual image of an object.

The -ve value of magnification represents real image of an object.


Q: Using magnification formula, prove that image formed by a plane mirror is at the same distance as object but behind the mirror. It is given that in plane mirror, object height and image height are equal.


Friday 8 September 2017

CBSE Class 10 - Light - Reflection From Mirrors (Worksheet) (#cbseNotes)

Light - Reflection From Mirrors (Worksheet)

CBSE Class 10 - Light - Reflection From Mirrors (Worksheet) (#cbseNotes)



1. We get a diminished image with a concave mirror when the object is placed ____.


2. The drivers mirror used in automobiles is ____.


3. The distance of focus F from the pole P is termed as the ..................... of the mirror.


4. Mirror formula is ____.


Saturday 17 June 2017

CBSE Class 10 - Physics - Electricity - (Holiday Assignment) (#cbseNotes)

Electricity - (Holiday Assignment)

CBSE Class 10 - Physics - Electricity - (Holiday Assignment) (#cbseNotes)


Q1: Two metallic wires A and B of same material are connected in parallel. Wire A has length l and radius r and wire B has length 2l and radius 2r. Compare the ratio of the total resistance of parallel combination and the resistance of wire A.

Answer:
Wire A:
Length = l
Radius = r
Area   = πr²
R₁   = ρ  x l /(πr²)

Wire B:
Length = 2l
Radius = 2r
Area = π(2r)² = 4πr²
R₂   = ρ  x 2l /(4πr²) = ρ  x l /(2πr²)

Let Rₚ = effective resistance of parallel combination
1/Rₚ = 1/R₁ + 1/R₂

1/Rₚ = (πr²)/ρl + (2πr²)/ρl

Rₚ = ρl/(3πr²)

Friday 2 June 2017

CBSE Class 10 - Science - CH 14 Sources of Energy (Important Differences) (#cbseNotes)

Sources of Energy (Important Differences) 

CBSE Class 10 Science - CH 14 - Sources Of Energy


Fossil Fuels Energy vs Solar Energy

Fossil Fuels Energy Solar Energy
1. Fossil energy can be used day or night. Can be used in day time. We need to store its energy to use it at night.
2. The stock of fossil energy is limited. e.g. coals will last for next 200 years. Sun’s energy is unlimited.
3. Fossil energy is non-renewable. It takes millions of year to produce fossil fuel. Solar energy is renewable source of energy.
4. Give pollution. Pollution Less
5. Fossil fuels release energy when they are burnt in air. Solar radiation carry packets of energy due to fusion reaction in the sun.


Sunday 30 April 2017

CBSE Class 10 - Physics - Electricity - Important Points To Remember (#cbsenotes)

Electricity - Important Points To Remember 

CBSE Class 10 - Physics - Electricity - Important Points To Remember (#cbsenotes)

CBSE Class 10 - Physics 

Electric current is defined as the amount of charge flowing through a particular cross section area in a unit time.


The SI unit of electric current is ampere.


A stream of electrons moving through a conductor constitutes an electric current. In a conventional current, the direction of current is taken opposite to the direction of flow of electrons i.e. flow of positive charges from +ve terminal to -ve terminal.


1 A is the flow of 6.25 × 10¹⁸ electrons per second, or 1 coulomb per second.


Thursday 5 May 2016

CBSE Class 10 - Physics - CH 12 Electricity (Worksheet)

Electricity

CBSE Class 10 - Physics - CH 12 Electricity (Worksheet)

Worksheet


Fill in the blanks

1. The source of all electricity is ______. It’s SI unit is _________.


2. The net charge flowing through a cross section of a conductor in unit time is called ________.


3. Electric potential difference between points in an electric circuit is the ______ _______ to move a unit charge from one point to other. i.e. 1V = ____/1C.


4. Current is measured in Amperes using _______.


5. If 90 coulombs charge passes through the conductor for 5 minutes, then the current in the conductor is _____.


6. A _________ is an electronic measuring instrument the combines several measuring functions (electric potential difference, electric current and electric resistance) in one unit.


Wednesday 4 November 2015

CBSE Class 10 - Physics - Reflection of Light By Plane and Spherical Mirrors (V Short Q and A)


Reflection of Light By Plane and Spherical Mirrors

CBSE Class 10 - Physics - Reflection of Light By Plane and Spherical Mirrors (V Short Q and A)
Laughing Mirrors use combination of Spherical Mirrors and Plane Mirrors.
Is this image real or virtual?

Very Short Question Answers (Based on NCERT Chapter)


Q1: What is the position of the object, when we get a diminished image with a concave mirror?

Answer: Beyond C (centre of curvature)


Q2: What are Marginal rays?

Answer: The rays which strike the mirror surface near the periphery are called marginal rays.


Q3: What type of rear mirrors are used by drivers in automobiles?

Answer: Convex mirrors


Q4: What is the relation between the radius of curvature (R) and focal length (f) of a concave mirror?

Answer: R = 2f


Q5: What is a focal length in case of spherical mirrors?

Answer: It is the distance between focal length and focus.


Q6: An object is moving with a speed v towards a plane mirror, what is the speed of the image?

Sunday 27 October 2013

CBSE Class 10 - Science - Ch 11 - The Human Eye and the Colourful World (MCQs)

The Human Eye and the Colourful World
CBSE Class 10 - Physics - CH11: The Human Eye and the Colourful World (NCERT Q & A)
Dispersion of Light
Which light bends the most?
credits:wpclipart
(MCQs)

Q1: By which optical phenomenon, the splitting of white light into seven constituent colours occur?
(a) Refraction
(b) Reflection
(c) Dispersion
(d) Interference


Q2: A human eye can focus on objects at different distances by adjusting the focal length of the eye lens. This phenomenon is due to:

(a) near sightedness
(b) long sightedness
(c) accomodation
(d) persistence of vision


*Q3: Which of the following are the primary colours?
(a) Red, Blue, Yellow
(b) Red, Green, Violet.
(c) Yellow, Green Blue
(d) Red, Green, Blue


Q4(NCERT): The human eye forms the image of an object at its
(a) cornea
(b) iris
(c) pupil
(d) retina

Friday 26 July 2013

Class 10 - Science - CH13 - Magnetic Effects of Electric Current (MCQs)

Magnetic Effects of Electric Current
Magnetic field in wire loop
credits:openclipart

MCQs


Q1: Inside the magnet the field lines run

(a) From south to north
(b) Away from north pole
(c) From north to south
(d) Away from the south pole


Q2: An electric charge in uniform motion produces:

(a) an electric field only
(b) a magnetic field only
(c) both electric and magnetic fields
(d) no such field at all


Q3: The magnetic field inside the solenoid is

(a) Non uniform
(b)Variable
(c) same at all points
(d) zero

Monday 25 March 2013

CBSE Class 10 - CH 12 - Electricity (MCQs)

Electricity
An electric circuit

MCQs

Q1: The SI unit of electric charge is __________

(a) volts (V)
(b) ampere (A)
(c) coulomb (C)
(d) tesla (T)


Q2: By convention, the charge on a glass rod that has been rubbed with silk is called

(a) Positive
(b) Negative
(c) either positive or negative
(d) none of these


Q3: Two charged bodies having equal potential are connected through a conducting wire, in this case

(a) current will flow
(b) current will not flow
(c) cannot say
(d) current will flow if a resistor is also connected.


Friday 11 January 2013

CBSE Class 10 - Science - CH 16 - Management of Natural Resources (Q and A)

Management of Natural Resources
Management of Natural Resources
Why do we need to use our resources carefully?

Q & A

Q1(CBSE 2011): What is coliform bacteria? What does its presence in water indicate?

Answer: Coliform is a group of bacteria which is found in human intestines. Its presence in water indicates contamination by disease-causing microbes. Its high presence in rivers and ponds elevates the risks of water borne diseases like gastroenteritis.

Q2(CBSE 2011): State two reasons of launching "Ganga Action Plan". Which bacteria was found in Ganga water indicating contamination?

Saturday 15 December 2012

CBSE Class 10 - Physics - CH11: The Human Eye and the Colourful World (NCERT Q & A)

The Human Eye and the Colourful World
CBSE Class 10 - Physics - CH11: The Human Eye and the Colourful World (NCERT Q & A)
Dispersion of Light
Which light bends the most?
credits:wpclipart
(NCERT Chapter Q & A, Other Questions asked in CBSE Exam)

Q1(NCERT): What is meant by power of accommodation of the eye?

Answer: Power of accommodation is the ability of the eye lens to focus near and far objects clearly on the retina by adjusting its focal length. Power of accommodation of the eye is limited. It implies the focal length of the eye lens cannot be reduced beyond certain minimum limit.

Q2(CBSE 2011): A person cannot see the objects distinctly, when placed at a distance less than 50 cm.
(a) Identify the defect of vision.
(b) Give two reasons for this defect.
(c) Calculate the power and nature of the lens he should be using to see clearly the object placed at a distance of 25 cm from his eyes.
(d) Draw the ray diagrams for the defective and the corrected eye.


Answer: (a) Defect of vision = Hypermetropia  or Long-sightedness

Sunday 9 December 2012

CBSE Class 10 - Physics - CH11: The Human Eye and the Colourful World (Worksheet)

The Human Eye and the Colourful World
Human Eye
credits:openclipart
(Worksheet)

Fill in the blanks

1. The transparent spherical membrane covering the front of the eye is called ____________.

2. _______ is the surface which acts as screen and image is formed on it.

3. The coloured diaphragm between cornea and lens is known as __________.

4. A small hole in iris which controls the intensity of light entering the eye is called __________.

Friday 31 August 2012

Class 10 - Science - CH13 - Magnetic Effects of Electric Current

Magnetic Effects of Electric Current
Earth's Magnetic Field
(computer simulation)
credits: wikipedia

MCQs, Q & A from CBSE Papers

Q1: The two poles in a magnet have
(a) equal pole strength.
(b) unequal pole strength.
(c)  can be same or different
(d) None of these


Q2:A magnet AB is broken into two pieces. What is the polarity of A, B, C and D?

Monday 13 August 2012

CBSE Class 10 - Science - Ch14 - Sources of Energy

Sources of Energy 
(Q & A)

Q1: Fill in the blanks.
(a) Hydro power plants convert _________ energy of falling water into electricity.

(b) When wood is burnt in a limited supply of oxygen, ______ is left behind as residue.

(c) Gases like ______, _____, ______ and ______ are generated in a biogas plant.

(d) Biogas contains _____ % methane.

(e) To maintain the required speed of the turbine, wind speed should be higher than _____.

(f) To establish 1 MW generator, the wind energy farm needs about ___ hectares of land.

(g) Ocean Thermal Energy plants can operate if the temperature difference between the water at the surface and water at depths up to ______ km is _______ or more.

(h) ______ and _______ countries have number of power plants based on geothermal energy.

Answer:

Sunday 1 April 2012

Class 10 - Science - Ch12 - Electricity - Q & A

Electricity
Class 10 - Science - Ch12 - Electricity - Q & A

Q & A
 
Q1: What type of charge does an ebonite rod acquire when it is rubbed with wool? What is
the nature of the charge acquired by wool?


Answer: Ebonite rod has a negative charge and woollen cap has an equal amount of positive charge.

Note: Charging by friction always produces equal and opposite charges on the twobodies which are rubbed in intimate contact.

Q2: What is the charge on an electron (e)?

Answer: -1.6 x 10 -19 Coulombs (C)


Q3: Define Coulomb's law.

Answer: The magnitude of the force of attraction (or repulsion) between two point charges is
directly proportional to the quantity of charge present on each of them and inversely
proportional to the square of the distance separating them.

Let q1 and q2 be two like charges separated by a distance d, then the two charges will continue to repel each other with a force (F). Mathematically it is represented as:


Q4: What is the SI unit of charge? Is it a scalar or vector quantity?
Answer: SI unit of charge is Coulomb (C). It is a scalar quantity.