Class – XI

 Session: 2021-22

                                                                                                   Sample paper - 1

 

General Instructions:

1. All questions are compulsory. There are 37 questions in all.
2. This question paper has 4 sections: Section-A, Section-B, Section-C & Section-D.
3. Section A contains 20 questions of one mark.
4. Section-B contain 7 questions of 2 marks.
5. Section-C contains 7 questions of 3 marks
6. Section- D contains 3 questions of 5 marks each.
7. There is no overall choice.
8. Use of calculators is not permitted. However, you may use log tables if necessary.

 

SECTION - A

Question 1:                                                                                                                          

If momentum (P), Area (A), and time (T) are taken to be fundamental quantities, then energy has the dimensional formula. 

    (a) P^-1 A^-1 T^-1 

    (b) P² A¹ T¹

    (c) P¹ A ^(-1/2) T¹

    (d) P¹ A ^(1/2) T^-1

 

Question 2:                                                                                                                            

When a body is dropped from a tower, then there is an increase in its

(a) mass

(b) velocity

(c) acceleration

(d) potential energy

 

Question 3:                                                                                                                             

If a body A of mass M is thrown with velocity v at angle of 30° to the horizontal and another body B of the same mass is thrown with the same speed at an angle of 60° to the horizontal, the ratio of the horizontal ranges of A and B will be

(a) 1: 3

(b) 1: 1

(c) √3: 1

(c) 1: √3

 

Question 4:                                                                                                                           

The spring force is given by:

    (a) F=kx

    (b) F=k/x

    (c) F=(-k)/x

    (d) F= -kx

 

Question 5:                                                                                                                             

A bicyclist comes to a skidding stop in 10 m. During this process, the force on the bicycle due to the road is 200 N and is directly opposed to the motion. The work done by the cycle on the road is

(a) +2000 J

(b) -200 J

(c) zero

(d) -20,000 J

 

Question 6:                                                                                                                             

During inelastic collision between two bodies, which of the following quantities always remains conserved?

    (a) Total kinetic energy

    (b) Total mechanical energy

    (c) Total linear momentum

    (d) Speed of each body.

 

Question 7:                                                                                                                             

For which of the following does the centre of mass lie outside the body?

(a) A pencil

(b) A shotput

(c) A dice

(d) A bangle

 

Question 8:                                                                                                                           

A satellite is orbiting around the Earth with a period T. If the Earth suddenly shrinks to half its radius without change in mass, the period of revolution of the satellite will be

(a) T

(b) T²

(c) T√2

(d) 2T

 

Question 9:                                                                                                                           

The temperature of a wire is doubled. The Young’s modulus of elasticity

     (a) will also double

     (b) will become four times

     (c) will remain same

    (d) will decrease

 

Question 10:                                                                                                                            

The escape velocity of a body depends upon mass as:

    (a) m^o

    (b) m

    (c) m²

    (d) m³

 

Question 11:                                                                                                                            

Water waves produced by a motor boat sailing in water are:

    (a) neither longitudinal nor transverse

    (b) both longitudinal and transverse

    (c) only longitudinal

    (d) only transverse

 

Question 12:                                                                                                                            

A rectangular frame is to be suspended symmetrically by two strings of equal length on two supports. It can be done in one of the following 3 ways: the tension in the string will be then

    (a) The same in all cases

    (b) Least in (a)

    (c) Least in (b)

    (d) Least in (c)

 

Question 13:                                                                                                                          

Define one parallactic second. What is it value?

 

Question 14:                                                                                                                            

A person of mass 50 kg stands on a weighing scale on a lift. If the lift is descending with a downward acceleration of 9 m/s². What would be reading of weighing scale.?

 

Question 15:                                                                                                                            

Analyse the graph carefully and answer the given questions.

    (i) Which represents the higher velocity.

   (ii) Also, explain the reason behind this.

 

Question 16:                                                                                                                            

Iceberg floats in the water with the part of its submerged. What is the fraction of volume of iceberg submerged, if the density of ice is ρ_ice= 0.917 g/cm³?

 

Question 17:                                                                                                                            

A constant retarding force 50N is applied to a body of mass 20kg moving initially with a speed of 15 m/s. How long does the body take to stop?

 

Question 18:                                                                                                                            

A boy travelling in an open car moving on a levelled road with constant speed tosses a ball vertically up in the air and catches it back. Sketch the motion of the ball as observed by a boy standing on a footpath. Give explanation to support your diagram.

 

Question 19:                                                                                                                            

What are the properties of ideal fluid?

 

Question 20:                                                                                                                            

A faulty thermometer reads 5⁰C in melting ice and 99⁰C in steam. Find the correct temperature in ⁰F, when this faulty thermometer reads 52⁰C.

 

SECTION - B

Question 21:                                                                                                                    

Differentiate between static friction, limiting friction, kinetic friction.

 

Question 22:                                                                                                                            

A steel wire has a length of 12 m and a mass of 2.10 kg. what will be the speed of a transverse wave on this wire when a tension of 2.06 × 10⁴ N is applied.?

Question 23:                                                                                                                            

A coin is dropped in lift. It takes time t₁ to reach the floor when lift is stationary. It takes time t₂ when lifts is moving up with constant acceleration. Then relate t₁ & t₂.

 

Question 24:                                                                                                                            

What are the two basic characteristics of a SHM?

 

Question 25:                                                                                                                            

Two molecules of a gas have speeds of 9 ×  m/s and 1×  m/s respectively. What is the root mean square speed of these molecules?

 

Question 26:                                                                                                                            

A body falls towards earth in air. Will its total mechanical energy be conserved during the fall? Justify.

 

Question 27:                                                                                                                            

The position time graph of a body of mass 2 kg is as given in fig. what is the impulse on the body at t= 0s and t= 4s.

 

SECTION - C

Question 28:                                                                                                                            

Write the characteristic of (i) Longitudinal waves (ii) Transverse waves 

 

Question 29:                                                                                                                            

Two cars A & B approach a stationary observer from opposite sides as shown in figure. Observer hears no beat. If the frequency of the horn of the car B is 504 Hz, then what is frequency of horn of car A?

 

Question 30:                                                                                                                            

A raindrop of mass 1 g falling from a height of 1 km hits the ground with a speed of 50 m/s. Calculate

    (a) Loss of P.E of the drop

    (b) The gain in K.E of the drop

    (c) Is the gain in K.E. equal to loss of P.E.? If not why. (Take g= 10 m/s²)

 

Question 31:                                                                                                                            

Why does a gas not possess a unique or single specific heat? Discuss the limits of specific heat of a gas.

 

Question 32:                                                                                                                            

Give the reason for the following questions:

(i) The motion of an artificial satellite around the earth cannot be taken as SHM.

    (ii) A passing aeroplane sometimes causes the rattling of the windows of house.

    (iii) The time period of a simple pendulum will get doubled if its length is increased 4 times.

 

Question 33:                                                                                                                            

If the coefficient of performance of a refrigerator is 5 and operates at the room temperature (27°C ), Find the temperature inside the refrigerator.

 

Question 34:                                                                                                                           

    (i) Determine the temperature at which rms speed of CO₂ gas molecule will be equal to 1 km/s. Given the molecular mass of    CO₂ is 44.

    (ii) Calculate the rms speed of a hydrogen gas molecules at STP. Given that the density of hydrogen at STP is 0.09 kg/m³.

 

SECTION - D

Question 35:    

State and prove Bernoulli’s principle for the flow of non-viscous fluids.                                                                                                          

 

Question 36:                                                                                                                            

(a) State and explain Charles’ law.

(b) State and derive the ideal gas equation.

 

Question 37:                                                                                                                            

Explain why:

(a) To keep a piece of paper horizontal, you should blow over, not under it.

(b) When we try to close a water tap with our fingers, fast jets of water gush through the openings between our fingers.

(c) The size of the needle of a syringe controls the flow rate better than the thumb pressure exerted by a doctor while administering an injection.

(d) A fluid flowing out of a small hole in a vessel result in a backward thrust on the vessel.

(e) A spinning cricket ball in air does not follow a parabolic trajectory.

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