PHYSICS, CHEMISTRY IMPORTANT QUESTION FOR EXAM 2021 Class 11th

 Multiple choice questions: 

Light year is the unit of 

A) Intensity of light  

B) distance

C) velocity

D) time

The number of significant terms in 3400 is 

A) 7 

B) 6

C) 4

D) 2

Which of the following quantity is expressed as force per unit area 

A) Work

B) pressure

C) volume

D) area

Identify the vector quantity among the following 

A) Heat

B) angular momentum 

C) distance

D) energy

The angle of projection for a projectile thrown parallel to horizontal 

A) 30° 

B) 0°

C) 45°

D) 90°

Force responsible for the circular motion is 

A) Centripetal force 

B) centrifugal force 

C) gravitational force 

D) none of these

A particle revolves arounda circular path. The acceleration of the particle is inversely proportional to

A) Radius

B) velocity

C) mass of the particle 

D) both b and c 

If dot product of two vectors is zero,then the vectors are 

A) Parallel to each other 

B) anti parallel to each other 

C) perpendicular to each other 

D) none of these 

The centre of mass of a system of particles does not depend upon 

A) Masses of the particles

B) forces on the particles 

C) position of the particles

D) relative distance between the particles

A circular disc is rotating with angular velocity w. If a mass standing at 

A) Is not changed 

B) is halved 

C) decreases

D) increases

True/ False

The speed of sound in vacuum is 232ms".

 Absolute zero is the condition, at which molecular motion ceases.

  Height of geostationary satelite above the surface of earth is approximately 3600Okm. 

Kinetic friction  is a self adjusting force. 

Magnitude of the unit vector is always 1

2 Marks Questions: 

What are the four types of systems of units? 

Define scalar and vector quantities. Give examples also. 

A body starts from rest and acquires a velocity of 12m/s in 5 seconds. Calculate acceleration and distance moved. 

When the work done is said to be negative? Give example. 

The bags and suitcases are provided with broad handles. Explain, why? 

A gas has two specific heats, whereas a liquid and solid have only one. Why? 

All molecular motion ceases at 0K. Explain. 

Two unequal springs of the same material are loaded with the same load. Which one will have a larger value of time period? 

3 Marks Question

Write three advantages and three disadvantages of friction.

The roadway bridge over a canal is in the form of an arc of a circle of radius 20m. What is the maximum speed with which a car can cross the bridge without leaving contact with the ground at the highest point? 

Define kinetic energy. Derive an expression for it. 

State law of conservation of angular momentum.How does an ice-skater, a ballet dancer or an acrobat take advantage of the principle of conservation of angular momentum. 

Define escape velocity. Derive an expression for it in terms of radius Rof the earth and acceleration due to gravity. 

An artificial satellite is getting around the earth at a distance of 1,600 km. Calculate the period of revolution and orbital velocity. Given radius of the earth 6,400 Km and g 9.8ms2 

gas is suddenly compressed to of its volume. Calculate rise in Temperature,original temperature being 27°C and y =1.5 

What is a simple pendulum? Derive an expression for the time period of a simple pendulum. 

5 Marks Question: 

State parallelogram law of vector addition. Derive an expression for the resultant of two vectors P and Q inclined at an angle of 0° with each other. 

projectile is fired with a certain initial velocity u making an angle 0° with the horizontal. Find the maximum height attained, total time of flight and the horizontal range. 

State and prove Bernoulli's theorem and give its one practical application. 

Derive capillarity. Derive an expression for the rise of liquid in a capillary tude

CHEMISTRY

The mass of an atom of sodium is 

The molecular mass of NH4OH is 

Give the no. of electrons in the species O2t 

What is the shape of PH3 molecule 

Energy can neither be created nor be destroyed. It is 

the enthalpy change accompanying the conversion of one mole solid substance into the liquid state at its melting point 

Hydrogen gas is prepared in laboratory by action of which metal with dilute sulphuric acid 

The product formed in the reaction Co(g) + 2H2(g) ? 

Which molecule has highest magnitude of hydrogen bonding 

In the reaction PCls(g)>PCl3(g)}+Cl2(g). if equilibrium is subjected to a decrease in pressure by increasing the volume,mole of reaction products will

Which is a non electrolyte? 

Correct order of increasing basic character is 

Which of the following alkali metal gives hydrated salts? 

Laboratory preparation of methane is by mixture of sodium acetate with 

The general formula of alkanes is 

Read the given passage and answer the following questions: 

The p-Block Elements comprise those belonging to Group 13 to 18 and these together with the s-Block Elements are called the Representative Elements or Main Group Elements. The outermost electronic configuration varies from ns2np1 to ns2np6 in each period. At the end of each period is a noble gas element with a closed valence shell ns2np6 configuration.All the orbitals in the valence shell of the noble gases are completely filled by electrons and it is very difficult to alter this stable arrange ment by the addition or removal of electrons. The noble gases thus exhibit very low chemical reactivity.Precedingthe noble gas family are two chemically important groups of non-metals.They are the halogens (Group 17) and the chalcogens (Group 16).These two groups of elements have highly negative electron gain enthalpies and readily add one or two electrons respectively to attain the stable noble gas configuration. The non-metallic character increases as we move from left to right across a period and metallic character increases as we go  down the group. 

Q. What are representative elements? 

Q. Name two groups which have high negative gain enthalpy. 

Q. Name two groups of non-metals in periodic table. 

True False

water which contains cations and anions is called demineralized water. 

A catalyst does not effect the position of equilibrium because it increases the rate of forward and backward reactions equally. 

1 calorie = 4.814 joules 

Dry ice is solid sulphur dioxide. 

Magnesium belongs to group called alkaline earth metals. 

The properties of system which depends upon quantity of the substance present in the system are called extensive properties. 

Lewis acid are those substance which give electron pairs. 

Temporary hardness of water may be removedby adding CaSO4

Alkali metals lose electrons in S orbita

The number of water molecule in Mohr's salt is 8. 

Two marks question

Q.State Pauls' exclusion principle. 

Q.State Aufbau Principle. 

Q. State Charle's Law. 

Q. Assuming complete dissociation, calculate the pH of 0.003M HCI 

Q. The concentration of hydrogen ion in sample of soft drink is 3.8 X 103 M. What is the pH value? 

Q. What is the oxidation number of sulphur in: 

(i) H2S04 

NazS203 

Q. The first ionization enthalpies of alkaline earth metals are higher than those of 8. corresponding alkali metals. Explain. 

Q. Discuss the laboratory preparation of methane. 

3 Marks question

Q. The empirical formula and molecular formula mass of a compound are CH20 and 180g respectively. what will be the molecular formula of a compound? 

Q. Solution is prepared by adding 60g of methyl alcohol to 120g water. Calculate the mole fraction of methanol and water. 

Q. A balloon is filled with hydrogen at room temperature .It will burst if pressure exceeds 0.2bar .If at 1bar pressure, the gas occupies 2.27L volume,upto what volume can the balloon be expanded? 

Q. What do you understand by Homolytic fission and Heterolytic fission? 

5 Marks Question

Q. Write three difference between sigma and pi bond. 

ii) What do you understand by bond pairs and lone pairs. 

Q. On the basis of VSEPR theory,predict the shapes of NH3 and H20. 

ii) Define Hybridisation ? write two necessary conditions for hybridization. 

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