Courses

# Physics Past Year Paper Compartment Anskey (Outside Delhi Set -3) - 2014, Class 12 Class 12 Notes | EduRev

Created by: Ambition Institute

## Class 12 : Physics Past Year Paper Compartment Anskey (Outside Delhi Set -3) - 2014, Class 12 Class 12 Notes | EduRev

``` Page 1

Compartment Page No. 1 20th July, 2014 Final
MARKING SCHEME
SET 55/3 (Compartment)
Q.No. Expected Answer/Value Points Marks Total
Marks
1. Line B
Since slope (q/V) of B is lesser than that of A.
½
½ 1
2. Demodulation is the process of retrieval of information from the carrier wave at the
receiver end.
1 1
3.
1
1
4. A has positive polarity 1 1
5.
=
1 1
6.
=   where   is speed of electron
Alternatively:
=
1
1
7. In point to point communication, communication takes place over a single link
between a transmitter and a receiver.
In the broadcast mode, there are a large number of receivers corresponding to a
single transmitter.
½
½
1
8. With increase in temperature, the relaxation time ( average time between successive
collisions) decreases  and hence resistivity increases.
Alternatively:
Resistivity     increases as  decreases with increase in temperature.
1
1
9

(i) According to Biot Savartâ€™s law, the magnetic field due to a current element
carrying current I at a point with position P vector  is given by
=
1
(i) Statement of Biot Savartâ€™s law 1
(ii) Expression for magnetic field ½
(iii) Showing field lines  ½
Page 2

Compartment Page No. 1 20th July, 2014 Final
MARKING SCHEME
SET 55/3 (Compartment)
Q.No. Expected Answer/Value Points Marks Total
Marks
1. Line B
Since slope (q/V) of B is lesser than that of A.
½
½ 1
2. Demodulation is the process of retrieval of information from the carrier wave at the
receiver end.
1 1
3.
1
1
4. A has positive polarity 1 1
5.
=
1 1
6.
=   where   is speed of electron
Alternatively:
=
1
1
7. In point to point communication, communication takes place over a single link
between a transmitter and a receiver.
In the broadcast mode, there are a large number of receivers corresponding to a
single transmitter.
½
½
1
8. With increase in temperature, the relaxation time ( average time between successive
collisions) decreases  and hence resistivity increases.
Alternatively:
Resistivity     increases as  decreases with increase in temperature.
1
1
9

(i) According to Biot Savartâ€™s law, the magnetic field due to a current element
carrying current I at a point with position P vector  is given by
=
1
(i) Statement of Biot Savartâ€™s law 1
(ii) Expression for magnetic field ½
(iii) Showing field lines  ½
Compartment Page No. 2 20th July, 2014 Final
(ii) B =
Field lines
½
½
2
10.

a) An electromagnet consists of a core made of a ferromagnetic material placed
inside a solenoid. It behaves like a strong magnet when current flows through
the solenoid and effectively loses its magnetism when the current is switched
off.
(i) A permanent magnet is also made up of a ferromagnetic material but it
retains its magnetism at room temperature for a long time after being
magnetized once.
b)
(i) High permeability
(ii) Low retentivity
(iii)Low coercivity
(Any two)
[Note: Give ½ mark if the student just writes â€˜soft ironâ€™ is a suitable material for
making electromagnets.]
½
½
½+ ½
2
11.
Let P be the required point at  a distance x from charge q
½
½
(a) Difference between a permanent magnet and an electromagnet ½ + ½
(b) Any two properties of material  ½ + ½
Formula  ½
Substitution and simplification 1
Result  ½
Page 3

Compartment Page No. 1 20th July, 2014 Final
MARKING SCHEME
SET 55/3 (Compartment)
Q.No. Expected Answer/Value Points Marks Total
Marks
1. Line B
Since slope (q/V) of B is lesser than that of A.
½
½ 1
2. Demodulation is the process of retrieval of information from the carrier wave at the
receiver end.
1 1
3.
1
1
4. A has positive polarity 1 1
5.
=
1 1
6.
=   where   is speed of electron
Alternatively:
=
1
1
7. In point to point communication, communication takes place over a single link
between a transmitter and a receiver.
In the broadcast mode, there are a large number of receivers corresponding to a
single transmitter.
½
½
1
8. With increase in temperature, the relaxation time ( average time between successive
collisions) decreases  and hence resistivity increases.
Alternatively:
Resistivity     increases as  decreases with increase in temperature.
1
1
9

(i) According to Biot Savartâ€™s law, the magnetic field due to a current element
carrying current I at a point with position P vector  is given by
=
1
(i) Statement of Biot Savartâ€™s law 1
(ii) Expression for magnetic field ½
(iii) Showing field lines  ½
Compartment Page No. 2 20th July, 2014 Final
(ii) B =
Field lines
½
½
2
10.

a) An electromagnet consists of a core made of a ferromagnetic material placed
inside a solenoid. It behaves like a strong magnet when current flows through
the solenoid and effectively loses its magnetism when the current is switched
off.
(i) A permanent magnet is also made up of a ferromagnetic material but it
retains its magnetism at room temperature for a long time after being
magnetized once.
b)
(i) High permeability
(ii) Low retentivity
(iii)Low coercivity
(Any two)
[Note: Give ½ mark if the student just writes â€˜soft ironâ€™ is a suitable material for
making electromagnets.]
½
½
½+ ½
2
11.
Let P be the required point at  a distance x from charge q
½
½
(a) Difference between a permanent magnet and an electromagnet ½ + ½
(b) Any two properties of material  ½ + ½
Formula  ½
Substitution and simplification 1
Result  ½
Compartment Page No. 3 20th July, 2014 Final
=
x=
required point is at a distance  from charge q
Alternatively:
2 =  or
At distance d towards left of charge q
OR
(i) We have W =
W =
=
= -2
(ii)    for
Alternatively:
½
½
½
½
½
½
½
½
1
2
2
12.

Difference between emf( ) and terminal voltage (v)
terminal voltage
1) It is the potential difference
between two terminals of the cells
when no current is drawn from it.
2) It is the cause.
1) It is the potential difference
between two terminals when
current passes through it.
2) It is the effect.
½
One difference between  and V ½
VI Graph ½
Determination of â€˜râ€™ and  1
(i) Work Done 1
(ii) Orientation 1
Page 4

Compartment Page No. 1 20th July, 2014 Final
MARKING SCHEME
SET 55/3 (Compartment)
Q.No. Expected Answer/Value Points Marks Total
Marks
1. Line B
Since slope (q/V) of B is lesser than that of A.
½
½ 1
2. Demodulation is the process of retrieval of information from the carrier wave at the
receiver end.
1 1
3.
1
1
4. A has positive polarity 1 1
5.
=
1 1
6.
=   where   is speed of electron
Alternatively:
=
1
1
7. In point to point communication, communication takes place over a single link
between a transmitter and a receiver.
In the broadcast mode, there are a large number of receivers corresponding to a
single transmitter.
½
½
1
8. With increase in temperature, the relaxation time ( average time between successive
collisions) decreases  and hence resistivity increases.
Alternatively:
Resistivity     increases as  decreases with increase in temperature.
1
1
9

(i) According to Biot Savartâ€™s law, the magnetic field due to a current element
carrying current I at a point with position P vector  is given by
=
1
(i) Statement of Biot Savartâ€™s law 1
(ii) Expression for magnetic field ½
(iii) Showing field lines  ½
Compartment Page No. 2 20th July, 2014 Final
(ii) B =
Field lines
½
½
2
10.

a) An electromagnet consists of a core made of a ferromagnetic material placed
inside a solenoid. It behaves like a strong magnet when current flows through
the solenoid and effectively loses its magnetism when the current is switched
off.
(i) A permanent magnet is also made up of a ferromagnetic material but it
retains its magnetism at room temperature for a long time after being
magnetized once.
b)
(i) High permeability
(ii) Low retentivity
(iii)Low coercivity
(Any two)
[Note: Give ½ mark if the student just writes â€˜soft ironâ€™ is a suitable material for
making electromagnets.]
½
½
½+ ½
2
11.
Let P be the required point at  a distance x from charge q
½
½
(a) Difference between a permanent magnet and an electromagnet ½ + ½
(b) Any two properties of material  ½ + ½
Formula  ½
Substitution and simplification 1
Result  ½
Compartment Page No. 3 20th July, 2014 Final
=
x=
required point is at a distance  from charge q
Alternatively:
2 =  or
At distance d towards left of charge q
OR
(i) We have W =
W =
=
= -2
(ii)    for
Alternatively:
½
½
½
½
½
½
½
½
1
2
2
12.

Difference between emf( ) and terminal voltage (v)
terminal voltage
1) It is the potential difference
between two terminals of the cells
when no current is drawn from it.
2) It is the cause.
1) It is the potential difference
between two terminals when
current passes through it.
2) It is the effect.
½
One difference between  and V ½
VI Graph ½
Determination of â€˜râ€™ and  1
(i) Work Done 1
(ii) Orientation 1
Compartment Page No. 4 20th July, 2014 Final
(Any one) or any other relevant difference
Negative of slope gives internal resistance.
1
½ 2
13.
(i) For the AND gate:
Truth Table Logic Symbol
(ii) Output Waveform:
½ +½
1
2
14.
The condition for observing a rainbow are :
i. The sun comes out after a rainfall.
ii. The observer stands with the sun towards his/her back. (any one)
½
½
(i) AND gate Truth Table ½
Logic symbol ½
(ii) Output waveform 1
(a) Conditions ½ + ½
(b) Formation of rainbow
Diagram ½
Explanation ½
Page 5

Compartment Page No. 1 20th July, 2014 Final
MARKING SCHEME
SET 55/3 (Compartment)
Q.No. Expected Answer/Value Points Marks Total
Marks
1. Line B
Since slope (q/V) of B is lesser than that of A.
½
½ 1
2. Demodulation is the process of retrieval of information from the carrier wave at the
receiver end.
1 1
3.
1
1
4. A has positive polarity 1 1
5.
=
1 1
6.
=   where   is speed of electron
Alternatively:
=
1
1
7. In point to point communication, communication takes place over a single link
between a transmitter and a receiver.
In the broadcast mode, there are a large number of receivers corresponding to a
single transmitter.
½
½
1
8. With increase in temperature, the relaxation time ( average time between successive
collisions) decreases  and hence resistivity increases.
Alternatively:
Resistivity     increases as  decreases with increase in temperature.
1
1
9

(i) According to Biot Savartâ€™s law, the magnetic field due to a current element
carrying current I at a point with position P vector  is given by
=
1
(i) Statement of Biot Savartâ€™s law 1
(ii) Expression for magnetic field ½
(iii) Showing field lines  ½
Compartment Page No. 2 20th July, 2014 Final
(ii) B =
Field lines
½
½
2
10.

a) An electromagnet consists of a core made of a ferromagnetic material placed
inside a solenoid. It behaves like a strong magnet when current flows through
the solenoid and effectively loses its magnetism when the current is switched
off.
(i) A permanent magnet is also made up of a ferromagnetic material but it
retains its magnetism at room temperature for a long time after being
magnetized once.
b)
(i) High permeability
(ii) Low retentivity
(iii)Low coercivity
(Any two)
[Note: Give ½ mark if the student just writes â€˜soft ironâ€™ is a suitable material for
making electromagnets.]
½
½
½+ ½
2
11.
Let P be the required point at  a distance x from charge q
½
½
(a) Difference between a permanent magnet and an electromagnet ½ + ½
(b) Any two properties of material  ½ + ½
Formula  ½
Substitution and simplification 1
Result  ½
Compartment Page No. 3 20th July, 2014 Final
=
x=
required point is at a distance  from charge q
Alternatively:
2 =  or
At distance d towards left of charge q
OR
(i) We have W =
W =
=
= -2
(ii)    for
Alternatively:
½
½
½
½
½
½
½
½
1
2
2
12.

Difference between emf( ) and terminal voltage (v)
terminal voltage
1) It is the potential difference
between two terminals of the cells
when no current is drawn from it.
2) It is the cause.
1) It is the potential difference
between two terminals when
current passes through it.
2) It is the effect.
½
One difference between  and V ½
VI Graph ½
Determination of â€˜râ€™ and  1
(i) Work Done 1
(ii) Orientation 1
Compartment Page No. 4 20th July, 2014 Final
(Any one) or any other relevant difference
Negative of slope gives internal resistance.
1
½ 2
13.
(i) For the AND gate:
Truth Table Logic Symbol
(ii) Output Waveform:
½ +½
1
2
14.
The condition for observing a rainbow are :
i. The sun comes out after a rainfall.
ii. The observer stands with the sun towards his/her back. (any one)
½
½
(i) AND gate Truth Table ½
Logic symbol ½
(ii) Output waveform 1
(a) Conditions ½ + ½
(b) Formation of rainbow
Diagram ½
Explanation ½
Compartment Page No. 5 20th July, 2014 Final
Formation of a rainbow:
? The rays of light reach the observer through a refraction, followed by a
reflection, followed by a refraction.
? Figure shows red light, from drop 1 and violet light from drop 2,
reaching the observers eye.
½
½
2
15.
(i)
(ii)
½
½
½ + ½ 2
16.
½
½
1 2
17.
Flux through S
1
,
Flux through S
2
,  =
Ratio of flux = 1:3
No change in flux through S
1
with dielectric medium inside the sphere S
2

½
½
½
½ 2
(i) Source frequency â€“ Formula ½
Calculation and Result ½
(ii)       Quality Factor â€“Formula ½
-Calculation and Result ½
(ii)
De Broglie wavelength  ½
Calculation and Result 1½
Flux through S
1
½
Flux through S
2
½
Ratio   ½
Flux through S
1
with dielectric median ½
```
Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

;