motithang higher secondary school thimphu ... paper/2019...v) the body of mass 500g is moving with a...

MHSS/XI-PHYSICS/MT-2019/JD of 22

MOTITHANG HIGHER SECONDARY SCHOOL THIMPHU THROMDE

“Every child is inspired to learn and empowered with wisdom to excel in life”

Mid-Term: 2019 XI Physics (Theory) Writing Time: 3hour Date: Full marks: 100 Name: …………………………………………… Class & Sec. ……………… Roll No.: ……

Invigilator’s initial

Questions

For Teacher’s Use only Grand Total

Section A(40 marks) Section B(60)

1.a

1.b 1.c 1.d 1.e Q2 Q3 Q4 Q5 Q6 Q7 Q8

Award Teacher’s Initial

Total Marks awarded

Invigilator’s initial

READ THE FOLLOWING DIRECTIONS CAREFULLY

1. Do not write for the first 15 minutes. This time is to be spent reading the questions. 2. After having read the questions, you will be given three hours to answer all questions. 3. Answer all questions in section A. answer any six questions from section B. 4. The rough work should be done at the back of the page. 5. Remember to write quickly but neatly.

Grand total


Section A

Answer all questions

Question 1

a) Each question is followed by four possible choices of answer. Choose the correct answer and write it in your answer sheet. [15]

i) A ball is projected with Kinetic energy E at an angle of o45 to the horizontal. At the highest point during its flight, its kinetic energy will be a) Zero

b) 2E

c) 2

E

d) E ii) The velocity of projection of an oblique projectile is jiv 23 += ( sm / ). The speed of

the projectile at the highest point of the trajectory is a) sm /3 b) sm /2

c) sm /1 d) sm /0

e) iii) A particle moves with a velocity of smkjiv /)346( +−= under the influence of

constant force, ( ) .51520 NkjiF −+= The instantaneous power applied to the particle is a) W35 b) W45

c) W25 d) W195

e) iv) The work performed on an object does not depend upon the

a) Force applied b) Angle at which force is

inclined to the displacement

c) Initial velocity of the object d) Displacement

v) The body of mass 500g is moving with a velocity of 10m/sec. Then the momentum of the body is a) sec/5000gm b) sec/5.0 kgm

c) sec/5kgm d) sec/500kgm

vi) What is the maximum number of rectangular components into which a vector can be splits in its own plane? a) Two b) Three

c) Four d) More than four

vii) If kjiA 32 ++= and jiB −= 2 are two vector, then the angle between the vectors is

a) o90 b) o0

c) o60 d) o45


viii) A stone just released from the window of a train moving along a horizontal straight track. The stone will hit the ground following a a) Straight path b) Circular path

c) Parabolic path d) Hyperbolic path

ix) The unit of impulse is a) N b) Kg-m

c) Kg-m/s d) J

x) For inelastic collision between two spherical bodies a) The total kinetic energy is

conserved b) The total mechanical energy

is not conserved.

c) The linear momentum is not conserved.

d) The linear momentum is conserved.

xi) If the kinetic energy of a body is increased by 300%, the percentage change in momentum will be a) 100% b) 150%

c) 265% d) 73.2%

xii) Which of the following is the essential characteristic of a projectile

a) Initial velocity inclined to the horizontal

b) Zero velocity at the highest point

c) Constant acceleration perpendicular to the velocity

d) None of the above.

xiii) If a particle has different average velocities in different intervals then motion is said to be a) Uniform motion b) Non-uniform motion

c) Uniform or non-uniform motion

d) None of the above xiv) If A are B are two vectors and θ is the angle between them, if ( )BABA .3=× , the

value of θ . a) o45 b) o30

c) o90 d) o60

xv) You are driving a car at sm /20 at North East, you are driving both North and East at the same time. What is the speed in the East? a) sm /10 b) sm /5

c) sm /0 d) sm /40


b) Fill in the Blanks [5] i) A vector with magnitude …….......and an arbitrary direction is called null vector. ii) If velocity vector of a particle in x-y plane is ( ) ( ) ^2^ /2/5 jsmtistm + , then its

acceleration along the y-axis is…………………………….. iii) Work is ………….quantity and its SI unit is …………………… iv) 1kWh is equal to………………..joules. v) If…………is zero, a body continues to remain at rest. This property is called……

c) Match the items of column A with the items of column B. Rewrite the correct pairs in your answer sheet. [5] Column A Column B i. Object accelerate downward at a certain rate

(a) collision

ii. Slope of the tangent to the velocity-time graph at a particular instant of time.

(b) Instantaneous acceleration.

iii.Two vectors pointing in two opposite direction.

(c)commutative

iv. tFnet∆ (d)distributive v. Two or more bodies interact with each other and exert relatively stronger force on each other for relatively shorter time.

(e)Free-fall acceleration

vi.Two or more vectors in same line or can be brought in the same line by shifting in parallel direction

(f)Kinetic energy increases

vii. Dot product of two vectors (g) Conservation of mechanical energy viii.The law hold good in inertial as well as non-inertial frame of reference

(h) Impulse

ix.Shot fired from gun explodes in air (i) 2rMmGF =

x. Universal law of gravitation (j)Collinear Vectors (k)

rMmGF =

(l)Antiparallel vectors


Answer…. [5] Column A Column B i. Object accelerate downward at a certain rate

ii. Slope of the tangent to the velocity-time graph at a particular instant of time.

iii.Two vectors pointing in two opposite direction.

iv. tFnet∆ v. Two or more bodies interact with each other and exert relatively stronger force on each other for relatively shorter time.

vi.Two or more vectors in same line or can be brought in the same line by shifting in parallel direction

vii. Dot product of two vectors viii.The law hold good in inertial as well as non-inertial frame of reference

ix.Shot fired from gun explodes in air x. Universal law of gravitation

a) Correct the following statements [5] i) The measure of change in position of an object with time is known as distance.

………………………………………………………………………………………………………………………………………………………………………………

ii) For positive acceleration, the distance-time graph curve points downwards. ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

iii) The rectangular components of vector A along the x-axis is θsinAAx = and along the y-axis is θcosAAy = . ………………………………………………………………………………………………………………………………………………………………………………

iv) The SI unit of Force is sec/kgm . ……………………………………………………………………………………

v) Kilowatt-hour is the electrical unit of power. …………………………………………………………………………………


b) Answer the following questions: [10] i) What is a vector quantity?

………………………………………………………………………………………………………………………………………………………………………………

ii) State parallelogram law of vector addition. …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………........

iii) If two bodies stick together after collision, name the collision. ……………………………………………………………………………………………………………………………………………………………………………....

iv) Distinguish between elastic and inelastic collision. v) ………………………………………………………………………………………

……………………………………………………………………………………………………………………………………………………………………………....

vi) What is the amount of work done by a man pressing a rigid wall with a force of 200N? ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………....

vii) Two vectors, r and s, lies in the x-y plane. Their magnitudes are 4.5 units and 7.3 units, respectively, and their directions are o320 and o85 , as measured counterclockwise from the positive x-axis, what is the value of sr .r

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.................................................................................................................................... viii) Deduce an expression for Newton’s second law.

……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

ix) State the law of conservation of linear momentum? ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………


x) Why we should wear safety gear while visiting a construction site? ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………....

xi) Write one differences between distance and displacement. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Section B (60 marks) Answer any six questions

Question 2

a) Derive all three equations of kinematics for uniform motion by graphical method. [3] ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………


b) List three applications of dimensional analysis. [3] ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………....

c) Check the correctness of the equation asuv 222 =− [4]

Question 3

a) Derive an expression for parallelogram law of vector addition. [3]


b) Two forces 5N and 10N are o60 apart. Find the magnitude and resultant [3]


c) In a unit vector notation, what is the sum ba + if ( ) ( ) jmima 0.30.4 +=

rand

( ) ( ) jmimb 0.70.13 +−= . What are the magnitude and direction of ba + ? [4]

Question 4

a) Define Newton’s second law of motion and write its law in component form [3]


b) What is projectile motion? Mention two practical application of projectile motion. [3]

c) The position of the particle is given by ]533[ 3 kjttir ++= m. Find (i) the velocity and acceleration of the particle, (2) the magnitude of velocity and acceleration of the particle at st 5= [4]


Question 5

a) Derive an express for relation between power, force and velocity. [3]

b) An electric motor creates a tension of 4500N in hoisting a cable and reels it in at the rate of sm /2 . Calculate the power of the motor. [3]


c) Justify that work done is dot product of force and displacement. Write the conditions for positive and negative work done. [4]


Question 6

a) What is trajectory? Derive and expression for equation of trajectory for projectile. [3]


b) Write three applications of RADAR. [3]

c) The horizontal range of projectile is 34 times its maximum height. Calculate the angle of projection. [4]


Question 7

a) Divide 2.5684 by 1.32 and express the result in the correct significant figures. [3]

b) The time period of simple pendulum is function of mass of bob (m), effective length (l), and acceleration due to gravity (g). Deduce an equation for Time Period of simple pendulum using DIMENSIONAL ANALYSIS. [3]


c) You are to drive to an interview in another town, at a distance of 300km on an expressway. The interview is at 11:15 a.m. You plan to drive at 100km/hour, so you leave at 8:00 a.m. to allow some extra time. You drive at 100km, but then construction work forces you to allow to 40km/hour for 40km. What would be least speed needed for the rest of the trip to arrive in time for the interview? [4]


Question 8

a) The motion of the particle is described by the equation 2btax += where cma 15= and 2/3 scmb = .What is the instantaneous velocity at times 3s. [3]

b) A displacement vector r has a magnitude of mr 175= and points at an angle of o50relative to the axisx _ . Find the rectangular components of the vectors. [3]


c) Derive an expression for velocity of the rocket. [4]

motithang higher secondary school thimphu ... paper/2019...v) the body of mass 500g is moving with a...

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