kendriya vidyalaya rrc fatehgarh (up) holidays …

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KENDRIYA VIDYALAYA RRC FATEHGARH (UP)

HOLIDAYS HOMEWORK FOR AUTUMN BREAK

SESSION 2021-22

CLASS XII B

SUBJECT: PHYSICS

Q1 Solve the following question paper:

General Instructions:

(i) There are 35 multiple choice questions in all. All questions are compulsory.

(ii) This question paper has three sections: Section A, Section B and Section C.

(iii) Section A has eight MCQs based on the case study, Section B has seven assertion-

reasoning based MCQs and Section C has twenty MCQs.

(iv) Each question carries one mark.

(v) Use of calculators and log tables is not permitted.

(vi) You may use the following values of physical constants wherever necessary.

c = 3 × 108 m/s

h = 6.63 × 10−34 J s

e =1.6 × 10−19 C

µ0 = 4π × 10−7 T m A−1

ε0 = 8.85 × 10−12 C2 N−1 m−2 1

= 9 × 109 N m2 C-2 4πε0

Mass of electron (me) = 9.1 × 10−31 kg

Mass of neutron = 1.675 × 10−27 kg

Mass of proton = 1.673 × 10−27 kg

Avogadro’s number = 6.023 × 1023 per gram mole

Boltzmann constant = 1.38 × 10−23 J K−1

Section - A

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Capacitor

A capacitor is a system of two conductor

separated by an insulator. The two

conductors have charges + Q and − Q, and

potential difference V = V1 − V2 between

them.

The electric field in the region between the

conductors is proportional to the charge.

Consequently, V is also proportional to Q and the ratio Q/V is constant. This constant is called

the capacitance ‘C’ of the capacitor. The SI unit of capacitance is farad (F).

C is independent of Q or V. It depends only on the geometrical configuration of the system of

two conductors and nature of the insulator separating between them.

1. A 12 pF capacitor is connected to a battery of 6 V. The charge on the capacitor is

(a) 72 pC

(b) 2 pC

(c) 12 pC

(d) 72 µC

1

2. The parallel plate capacitor is charged up to a potential difference of V volts by a battery. After

disconnecting the battery, the separation between the two conductor is increased, then V

(a) decreases

(b) remains same

(c) becomes zero

(d) increases

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3. Two capacitors of capacitances 2 pF and 4 pF are connected in parallel. The total capacitance

of the combination is

(a) 4/3 pF

(b) 6 pF

(c) 3/4 pF

(d) 4 pF

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4. If a dielectric of dielectric constant ‘K’ is inserted between the plates of a capacitor while the

voltage supply remains connected, the energy stored in the capacitor

(a) remains same

(b) becomes U/K

(c) becomes KU

(d) becomes zero

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Acceptor Circuit

A tuned series LCR circuit is called an acceptor

circuit. By offering the minimum impedance to

current at resonant frequency it is able to select

or accept most readily a particular frequency at

many frequencies. Because at resonance, the

impedance of the circuit is at its smallest so

simply accept the current whose frequency is

equivalent to its resonant frequency.

In radio receivers, the resonant frequency of the circuit is tuned to the frequency of the signal

desired to be detected.

5. The following graph shows the variation of im with the frequency for a resonating circuit for

two cases (i) and (ii).

If A is impedance for case (i) and B for case (ii), then which of the following is true?

(a) A > B

(b) A < B

(c) A = B

(d) None of these

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6. In a series LCR circuit, the phase difference between current and voltage at resonance is

(a) /6

(b) /4

(c) 0

(d) /2

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7. A series LCR circuit is more selective when

(a) Both L and R are large

(b) Both L and R are small

(c) R is small and L is large

(d) L = R

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8. For a series LCR circuit with L = 2 H and C = 32 µF, the resonant frequency is

(a) 125 s−1

(b) 25 s−1

(c) 100 s−1

(d) 150 s−1

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Section - B

For Q. No.(s) 9 to 15, two statements are given, one labelled as Assertion (A) and the other

labelled as Reason (R). Select the most appropriate from the options given below:

(a) Both A and R are true and R is the correct explanation of A.

(b) Both A and R are true but R is not the correct explanation of A.

(c) A is true but R is false.

(d) Both A and R are false.

9. Assertion (A):

In a uniform electric field, an electric dipole experiences a torque.

Reason (R):

The net translatory force on an electric dipole in uniform electric field is zero.

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10. Assertion (A):

The surface of a conductor behaves as an equipotential surface.

Reason (R):

Any excess charge given to a conductor will reside at its surface.

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11. Assertion (A):

The mobility of charge carriers increases with increasing temperature.

Reason (R):

The resistance of the conductor decreases on increasing temperature.

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12. Assertion (A):

A wire of irregular shape placed in magnetic field as shown in the figure is turned into circular

shape. The direction of induced current is adcd.

Reason (R):

The flux through the surface increases during shape change, so induced current produces

opposing flux.

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13. Assertion (A):

A proton and an electron, with same momenta, enters in to magnetic field at right angles. The

radius of path followed by them is same.

Reason (R):

Radius is independent of mass of the particle.

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14. Assertion (A):

A compass needle when placed on the north magnetic pole of the earth, may lie in any direction.

Reason (R):

At poles, the horizontal component of earth’s magnetic field is zero.

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15. Assertion (A):

A lamp is connected to an ac source in series with a capacitor. The brightness of the lamp

increases when a metal sheet occupying the full volume of the capacitor is inserted inside the

capacitor.

Reason (R): The capacitive reactance is directly proportional to capacitance of the capacitor.

1

Section - C

16. A potentiometer can measure emf because

(a) the sensitivity of the potentiometer is large.

(b) no current is drawn from the cell at balance.

(c) no current is drawn from potentiometer wire at balance.

(d) internal resistance of the cell is neglected.

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17. If a positive charge is displaced against the electric field in which it was situated, then

(a) work will be done by the electric field on the charge.

(b) the intensity of the electric field decreases.

(c) energy of the system will decrease.

(d) energy will be provided by the external source displacing the charge.

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18. The electric flux emerging out from 1 C charge is

(a) 1/ε0

(b) 4

(c) 4/ε0

(d) ε0

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19. A cell of emf (E) and internal resistance (r) is connected to a variable external resistance R.

The graph of potential difference (V) as a function of R is

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20. A current I flows through a long straight conductor which is bent into a circular loop of radius

R in the middle as shown in the figure.

The magnitude of the net magnetic field at point O will be

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21. An electric dipole of dipole moment ‘p’ is placed parallel to the uniform electric field. The

amount of work done in rotating the dipole by 90⁰ is

(a) 2pE

(b) pE

(c) pE/2

(d) Zero

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22. Which of the following is not the property of an equipotential surface?

(a) They do not cross each other.

(b) The rate of change of potential with distance on them is zero.

(c) For a uniform electric field they are concentric spheres.

(d) They can be imaginary spheres.

1

23. Two point charges + 8q and − 2q are located at x = 0 and x = L respectively. The point on the

x-axis ( > L) at which the net electric field is zero due to these charges is

(a) 8L

(b) 4L

(c) 2L

(d) L

1

24. Drift velocity of the free electrons in a conducting wire carrying a current ‘I’ is ‘v’. If in a wire

of the same metal, but of double the radius, the current be 2I then the drift velocity of the electrons

will be

(a) v/4

(b) v/2

(c) v

(d) 4v

1

25. In a meter bridge experiment the ratio of left gap resistance to right gap resistance is 1:3. The

balance point from left is:

(a) 20 cm

(b) 25 cm

(c) 30 cm

(d) 35 cm

1

26. For a cell of emf 2 V, a balance is obtained for 50 cm of the potentiometer wire. If the cell is

shunted by a 2 Ω resistor and the balance is obtained across 40 cm of the wire, then the internal

resistance of the cell is

(a) 0.5 Ω

(b) 1 Ω

(c) 1.5 Ω

(d) 2 Ω

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27. The distance between the two current-carrying wires is doubled, then force between them is

(a) halved

(b) doubled

(c) tripled

(d) quadrupled

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28. A solenoid has 1000 turn per unit length. If a current of 5A is flowing through it, then magnetic

field inside the solenoid is

(a) 2 × 10−3 T

(b) 2 × 10−5 T

(c) 4 × 10−3 T

(d) 4 × 10−5 T

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29. To convert a galvanometer into ammeter of given range, we must connect

(a) a suitable low resistance in series

(b) a suitable low resistance in parallel

(c) a suitable high resistance in series

(d) a suitable high resistance in parallel

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30. Two wires of same length are shaped into a square and a circle if they carry same current, ratio

of magnetic moment is :

(a) 2 : π

(b) π : 2

(c) 4 : π

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(d) π : 4

31. If number of turns in primary and secondary coils is increased to two times each, the mutual

inductance

(a) becomes 4 times

(b) becomes 2 times

(c) becomes A times

(d) remains unchanged

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32. The current flows from A to B is as shown in the figure. The direction of the induced current in

the loop is

(a) clockwise

(b) anticlockwise.

(c) no emf is induced

(d) none of these

1

33. Which quantity is increased in a step-down transformer?

(a) Current

(b) Voltage

(c) Power

(d) Frequency

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34. The peak voltage of 220 V ac mains is

(a) 155 V

(b) 220 V

(c) 311 V

(d) 440 V

1

35. A transformer has 20 turns of primary and 100 turns of secondary. If the two ends of the primary

are connected to a 220 V ac supply, the voltage across the secondary is

(a) zero

(b) 1100 V

(c) 220 V

(d) 11 V

1

SUB- CHEMISTRY

1. Practice and solve CBSE sample paper along with two more sample papers.

2. Write the followimg named reactions-

Riemer- Tiemann, Sandmeyer’s reaction, Williamson’s synthesis, Swarts reaction, Wurtz, Fittig, Wurtz- Fittig reaction 3. Write distinguishing tests between-

Primary and secondary alcohol, alcohol and phenol 4. Write short notes on- Mutarotation, invert sugar, crystal defects, colligative properties, zwitter ion, structure of

nucliec acids, reducing and non reducing sugar, essential and non essential amino acids

5. Draw the structures of xenon compounds and mention their hybridisation.

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SUBJECT:- BIOLOGY

• PREPARE CBSE BOARD INVESTIGATORY PROJECT AS ASSIGNED INDIVIDUALLY

• SOLVE BOARD SAMPLE PAPER 2021-22 RELEASED BY CBSE (ALREADY SENT IN THE GROUP).

• COMPLETE BIOLOGY PRACTICAL RECORD FILE (WRITE TERM FIRST PRACTICALS WITH YOUR OBSERVATIONS and LABELLED DIAGRAMS)

• PRACTICE ASSERTION REASON AND CASE BASED QUESTIONS OF FIRST TERM SYLLABUS ( SENT IN THE GROUP)

• PREPARE FOR PRE BOARD EXAMINATION

SUBJECT: ENGLISH 1. Complete all the exercises of the lessons Done in the class in CW and HW as assigned. 2. Read and Revise all the lessons done in the class. 3. Solve two Sample Paper of Class 12th in a separate notebook. 4. Complete the exercises of Speaking and Listening Test.

Computer Science (Class XII)

1. Write Synopsis of the project assigned to you.

2. Prepare practical file (With at leaset 15 Function Programs and 15 File programs) for Term 1.

3. Prepare a Menu driven program to create a Calculaor functions (such as addition, subtraction, multiplication,

division, modulus, integer divistion, square root, power, floor) operations. Use function to perform all

operations.

For Ex.

Menu>

====== Welcome to calculation Section======

1. Addition

2. Subtraction

3. Multiply

4. Divide

5. Integer Division

6. …………. And so on

7. Exit

Enter your choice (1 for Addition, 2 for subtraction 3 for multiplication ……)

4. What do you mean by random number? In python which module is used to generate random number?

5. Give brief introduction about random module. Give Syntax, work and example of following random module

functions (i) random() (ii) randint() (iii) randrange()

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6. Write any 5 python programs using random module.

Note: For random module use class 11 CS Book

7. Write a Python program to write student details into a binary file named “student.dat”. Take the input from

the user.

Student Details: Student Name, Roll number, Marks

8. Write a Python program to display all record of student from above binary file (i.e. “student.dat”)

9. Write a Python program to search a record of student from above binary file (i.e. “student.dat”)

10. Write a Python program to update( modify) student record of above binary file (i.e. “student.dat”)

11. Write a Python program to delete a record of student from above binary file (i.e. “student.dat”)

Solution of question 7 for a help.

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शरद कालीन अवकाश गह कारय

ककषा बारहवी

ववषर हहिदी

१-आन वाली बोरय परीकषा म उपरोगी पसतक मिगान हत ववदयालर क पराचारय को एक परारयना पतर वलविए ।

२-,बढती जनसिखरा क कारण शहरो म बढत जनसिखरा घनतव स शहरो म उतपनन होन वाल सिकटो पर अपन ववचार वयकत करत हए

लगभग 150 शबदो म एक फीचर वलविए ।

३-दश म बढती महिगाई क कारण गरीब मजदरो क सामन उतपनन होन वाली समसराओ पर अपन ववचार वयकत करत हए 150 शबदो म

एक आलि वलविए ।

हहिदी की कॉपी म वलिाए गए पतरकाररता सिबिधी परशन उततर राद कीवजए ।

दो पज हहिदी की कॉपी म ककषा कारय साइर म बहत सिदर शबदो म सलि वलविए

kendriya vidyalaya rrc fatehgarh (up) holidays …

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