CBSE Class 12 Question Paper 2025 Solution Automotive

Marking Scheme
Strictly Confidential
(For Internal and Restricted use only)
Senior School Certificate Examination, 2025
SUBJECT NAME AUTOMOTIVE (Q.P. CODE 328)

General Instructions: -

1 You are aware that evaluation is the most important process in the actual and
correct assessment of the candidates. A small mistake in evaluation may lead to
serious problems which may affect the future of the candidates, education system
and teaching profession. To avoid mistakes, it is requested that before starting
evaluation, you must read and understand the spot evaluation guidelines carefully.
2 “Evaluation policy is a confidential policy as it is related to the confidentiality
of the examinations conducted, Evaluation done and several other aspects.
Its’ leakage to public in any manner could lead to derailment of the
examination system and affect the life and future of millions of candidates.
Sharing this policy/document to anyone, publishing in any magazine and
printing in News Paper/Website etc may invite action under various rules of
the Board and IPC.”
3 Evaluation is to be done as per instructions provided in the Marking Scheme. It
should not be done according to one’s own interpretation or any other
consideration. Marking Scheme should be strictly adhered to and religiously
followed. However, while evaluating, answers which are based on latest
information or knowledge and/or are innovative, they may be assessed for
their correctness otherwise and due marks be awarded to them. In class-X,
while evaluating two competency-based questions, please try to understand
given answer and even if reply is not from marking scheme but correct
competency is enumerated by the candidate, due marks should be awarded.
4 The Marking scheme carries only suggested value points for the answers
These are in the nature of Guidelines only and do not constitute the complete
answer. The students can have their own expression and if the expression is
correct, the due marks should be awarded accordingly.
5 The Head-Examiner must go through the first five answer books evaluated by each
evaluator on the first day, to ensure that evaluation has been carried out as per the
instructions given in the Marking Scheme. If there is any variation, the same should
be zero after delibration and discussion. The remaining answer books meant for
evaluation shall be given only after ensuring that there is no significant variation in
the marking of individual evaluators.
6 Evaluators will mark( √ ) wherever answer is correct. For wrong answer CROSS
‘X” be marked. Evaluators will not put right (✓)while evaluating which gives an
impression that answer is correct and no marks are awarded. This is most
common mistake which evaluators are committing.
7 If a question has parts, please award marks on the right-hand side for each part.
Marks awarded for different parts of the question should then be totaled up and

328 1 P.T.O.

written in the left-hand margin and encircled. This may be followed strictly.
8 If a question does not have any parts, marks must be awarded in the left-hand
margin and encircled. This may also be followed strictly.
9 If a student has attempted an extra question, answer of the question deserving
more marks should be retained and the other answer scored out with a note
“Extra Question”.
10 No marks to be deducted for the cumulative effect of an error. It should be
penalized only once.
11 A full scale of marks __________(example 0 to 80/70/60/50/40/30 marks as given
in Question Paper) has to be used. Please do not hesitate to award full marks if
the answer deserves it.
12 Every examiner has to necessarily do evaluation work for full working hours i.e., 8
hours every day and evaluate 20 answer books per day in main subjects and 25
answer books per day in other subjects (Details are given in Spot Guidelines).This
is in view of the reduced syllabus and number of questions in question paper.
13 Ensure that you do not make the following common types of errors committed by
the Examiner in the past:-
● Leaving answer or part thereof unassessed in an answer book.
● Giving more marks for an answer than assigned to it.
● Wrong totaling of marks awarded on an answer.
● Wrong transfer of marks from the inside pages of the answer book to the title
page.
● Wrong question wise totaling on the title page.
● Wrong totaling of marks of the two columns on the title page.
● Wrong grand total.
● Marks in words and figures not tallying/not same.
● Wrong transfer of marks from the answer book to online award list.
● Answers marked as correct, but marks not awarded. (Ensure that the right tick
mark is correctly and clearly indicated. It should merely be a line. Same is with
the X for incorrect answer.)
● Half or a part of answer marked correct and the rest as wrong, but no marks
awarded.
14 While evaluating the answer books if the answer is found to be totally incorrect, it
should be marked as cross (X) and awarded zero (0)Marks.
15 Any unassessed portion, non-carrying over of marks to the title page, or totaling
error detected by the candidate shall damage the prestige of all the personnel
engaged in the evaluation work as also of the Board. Hence, in order to uphold the
prestige of all concerned, it is again reiterated that the instructions be followed
meticulously and judiciously.
16 The Examiners should acquaint themselves with the guidelines given in the
“Guidelines for Spot Evaluation” before starting the actual evaluation.
17 Every Examiner shall also ensure that all the answers are evaluated, marks carried
over to the title page, correctly totaled and written in figures and words.
18 The candidates are entitled to obtain photocopy of the Answer Book on request on

328 2 P.T.O.

payment of the prescribed processing fee. All Examiners/Additional Head
Examiners/Head Examiners are once again reminded that they must ensure that
evaluation is carried out strictly as per value points for each answer as given in the
Marking Scheme.

328 3 P.T.O.

Set 4
MARKING SCHEME

AUTOMOTIVE

SECTION A
(Objective Type Questions) (30 Marks)

1. Answer any 4 out of the given 6 questions on Employability Skills. 41=4
(i) Appositive एपोजिजिव 1
(ii) (D) Books जिताबें 1
(iii) Dependent personality disorder आजित 1
(iv) (B) Autofill ऑिोजिल 1
(v) First Generation Entrepreneurs पहली पीढी उद्यमी 1
(vi) (A) respect socio-cultural authenticity of host country 1
मेिबान दे श िी सामाजिि-साां स्‍िृजति प्रमाजििता िा सम्‍मान िरना

2. Answer any 5 out of the given 7 questions. 51=5
(i) (B) low िम 1
(ii) Driving refreshing training certificate ड्राईजवांग ररर्फ््‍ेज‍ सांग िर े जनांग सजि‍ जििेि 1
(iii) (D) tyre shops िायर िी दु िानोां 1
(iv) (C) progressive प्रगजतशील 1
(v) Built in compressor जबल्‍ि इन िम्‍प्रैसर 1
(vi) (A) air and sand वायु और रे त 1
(vii) (B) tyre manufacturers िायर जनमा‍ ताओां 1

3. Answer any 6 out of the given 7 questions. 61=6
(i) (A) Positive caster सिारात्‍मि िैस्‍िर 1
(ii) (D) turning िजनिंग 1
(iii) come on road सड़ि पर आने 1
(iv) (B) steering स्‍िीयररां ग 1
(v) worm वम‍ 1
(vi) (A) output torque आउिपुि िॉि‍ 1
(vii) (D) lock to lock लॉि से लॉि 1
4. Answer any 5 out of the given 6 questions. 51=5
(i) (D) independent of से स्वतांत्र 1
(ii) (A) rolling रोजलांग 1
(iii) Challan clearance report चालान जनिासी ररपोि‍ 1

328 4 P.T.O.

(iv) (B) Transverse िर ान्‍सवस‍ 1
(v) resist the spring action स्प्रांग जिया िा जवरोध 1
(vi) (C) structural frame स्‍िर क्‍चरल र्फ्ेम 1

5. Answer any 5 out of the given 6 questions. 51=5
(i) (B) universal joint yokes यूजनवस‍ल िॉइां ि योक्स 1
(ii) (D) cross or spider िॉस या स्‍पाइड्र 1
(iii) (C) tripod िर ाइपोड् 1
(iv) Nitrogen Oxide (NOx) नाइिर ोिन ऑक्‍साइड् (NOx) 1

(v) half shafts or axle shaft हॉि शॉफ्ट् स 1
(vi) (A) small and medium छोिे और मध्‍यम 1

6. Answer any 5 out of the given 6 questions. 51=5
(i) Pulse width पल्‍स जवड्् थ 1
(ii) (A) limited सीजमत 1
(iii) (D) cutting in िजिां ग इन 1
(iv) (B) increases बढ 1
(v) (C) inlet port इनलेि पोि‍ 1
(vi) Emission उत्‍सि‍न 1

SECTION B
(Subjective Type Questions) (30 Marks)
Answer any 3 out of the given 5 questions on Employability Skills. Answer each
question in 20 – 30 words. 32=6

7. Exclamatory sentences are like declarative sentences, in that, they make a statement,
instead of asking question, but their main purpose is to express strong emotion. 2
जवस्‍मयाजदबोधि वाक्‍य घोषिात्‍मि वाक्‍योां िी तरह होते हैं , जिसमें वे प्रश्‍न पूछने िी बिाय
एि बयान दे ते हैं , लेजिन उनिा मुख्‍य उद्दे श्‍य मिबूत भावना व्‍यक्‍त िरना होता है ।

328 5 P.T.O.

8. Being present where we are, rather than where we are not, brings in peace and
calmness in our life. A calm and peaceful mind can help us achieve wonders. 2

हम िहााँ नहीां है वहााँ मौिू द रहने िी बिाय िहााँ हम हैं वहीां मौिूद रहने से हमारे िीवन में
शाां जत और स्प्सथरता आती है । एि शाां त और शाां जतपूि‍ जदमाग हमें चमत्‍िार हाजसल िरने में
मदद िर सिता है ।

9. (i) Title bar िाइिल बार 2
(ii) Menu bar मेन्‍यू बार
(iii) Standard bar स्‍िै न्‍ड्ड्‍ बार

10. The green jobs can limit the greenhouse emission: 2
(i) By reuse, reduce or recycle the waste
(ii) By using less heat and reconditioning
(iii) Using switch off light when not in use
(iv) By planting trees
हररत नौिररयााँ ग्रीन हाउस उत्‍सि‍न िो जनम्‍नजलस्प्ित प्रिार से सीजमत िर सिती है :
(i) वेस्‍ि िो ररयूि, ररड्यूस या ररसाइिल िरिे
(ii) िम ऊष्‍मा और ररिस्प्िशजनांग िा प्रयोग िरिे
(iii) ऑि बिन िा उपयोग िरिे
(iv) पेड़ लगािर

11. Decisiveness : 2
Decisiveness is ability to make profitable and quick decision. It becomes most
important while setting up a business venture. It is about identifying an opportunity
and acting on it.
जनि‍यशीलता लाभदायि और त्‍वररत जनि‍य लेने िी एि क्षमता है । व्‍यवसाजयि उद्यम
स्‍थाजपत िरते समय यह सबसे महत्त्‍वपूि‍ हो िाता है । यह एि अवसर िी पहचान िरने
और उस पर िाय‍ िरने िे बारे में है ।

Answer any 3 out of the given 5 questions in 20 – 30 words each. 32=6

12. Working Principle of Air Compressor: 2

328 6 P.T.O.

Air compressor collects and stores pressurized air in tank and uses pistons and valves
to achieve the appropriate pressure levels within an air storage tank that is attached
to the motorized unit.
एयर िम्‍प्रैसर दबाव वाली हवा िो िैं ि में एिजत्रत और सांग्रजहत िरता है और वायु भांड्ारि
िैं ि िे भीतर उजचत दबाव स्‍तर प्राप्‍त िरने िे जलए जपस्‍िन और वाल्व िा उपयोग िरता है ,
िो मोिर चाजलत इिाई से िुड़ा होता है ।
13. Disadvantages of Power Steering: 2
(i) The components used in the power steering assembly are more costly than
the ones used in the normal steering.

पावर स्प्ियररां ग असेंबली में उपयोग जिए िाने वाले घिि (पाि्‍ स) सामान्‍य स्‍िीयररां ग में
उपयोग जिए िाने वाले घििोां (पािों) िी तुलना में अजधि महां गे हैं ।
(ii) Increased complexity compared to manual steering
मैनुअल िीयररां ग िी तुलना में िजिलता में वृस्प्ि
(iii) Higher maintenance cost

उच्च रिरिाव लागत

14. Various types of Hydraulic shock absorbers: 2
(i) Telescopic shock absorber
(ii) Cam actuated piston type shock absorber
(iii) Rotary vane type shock absorber
(i) िे लीस्कोजपि शॉि एबिॉरबर
(ii) िैम एक्चुएिे ड् जपस्‍िन िाइप शॉि एबिॉरबर
(iii) रोिे री वेन िाइप शॉि एबिॉरबर

15. A universal joint forms a mechanical connection between the two shafts and allows
angular movement of one or both shafts. Also it transmits power smoothly from the
gear box to the differential. 2

एि यूजनवस‍ल िॉइां ि दो शाफ्टोां िे बीच एि मैिेजनि िनेक्‍शन बनाता है और एि या दोनोां
शाफ्टोां िे िोिीय (मूवमेंि) आां दोलन िी अनुमजत दे ता है । साथ ही जगयर बॉक्‍स से
जड्िरें जशयल ति पॉवर िो सुचारू रूप से पहाँ चाता है ।

16. Natural Sources of Emissions : 2

328 7 P.T.O.

Natural sources of emissions occur in nature without the influence of human beings.
The natural sources of emission may be wildfires, plants, wildlife and marine
aerosol, outgassing from the ocean.
उत्‍सि‍न िे प्रािृजति स्‍त्रोत मानव िे प्रभाव िे जबना प्रिृजत में होते हैं । उत्‍सि‍न िे
प्रािृजति स्‍त्रोत िांगल िी आग, पौधे , वन्‍यिीव और समुद्री एरोसोल हो सिते हैं ।
Decomposing vegetation and other biomass.

Answer any 3 out of the given 5 questions in 20 – 30 words each. 23=6

17. The differential is a mechanism by means of which outer wheels run faster than the
inner wheels, while taking a turn or moving over upheaval road. The differential
consists of a system of gears arranged in such a way that connects a propeller shaft
with the rear axles. 3

जड्िरें जशयल एि ऐसा तांत्र है , जिसिे माध्‍यम से मोड़ लेते समय या उथल-पुथल वाली सड़ि
पर चलते समय बाहरी पजहए िी तुलना में तेिी से चलते हैं । जड्िरें जशयल इस तरह से
व्‍यवस्प्सथत जगयर िी एि प्रिाली होती है िो प्रोपेलर शॉफ्ट िो पीछे िे एक्सल से िोड़ती है ।
18. 3
The purpose of fuel delivery system/control is to inject the correct and precise
amount of fuel in the intake manifold.
The fuel delivery system consists of the pipe (fuel rail), fuel injector,
fuel pressure regulator and fuel return pipe. Fuel is delivered from the tank to the
injector by means of an electric pump.
ईांधन जवतरि प्रिाली/जनयांत्रि िा उद्दे श्‍य इनिे ि मैजनिोल्‍ड् में ईांधन िी सही और सिीि
मात्रा िो इां िेक्‍ि िरना है । ईांधन जवतरि प्रिाली में पाइप (ईांधन रे ल) ईांधन इां िेक्‍िर फ्यूि
प्रसार रे गुलेिर ओर फ्यूि ररि‍ न पाइप शाजमल हैं । इलेस्प्ररि फ्यूि पांप िे माध्‍यम से ईांधन
िो िैं ि से इां िेक्‍िर ति पहाँ चाया िाता है ।

19. Various Advanced Technologies adopted in emission control: 3
(i) Modification of internal combustion engines to reduce the amount of
pollutants formed during fuel combustion.
(ii) Development of substitute fuels for petroleum-based fuels which will yield
low concentration of pollutants during combustion.
(iii) Addition of emission control devices to remove or to decompose pollutants in
harmless gases.
(i) इां िरनल िांब्यूशन इां िन से सांशोधन िा उद्दे श्‍य ईांधन िे िम्‍बूशन िे दौरान बनने
वाले प्रदू षिोां िी मात्रा िो िम िरना है ।

328 8 P.T.O.

(ii) पैिरोजलयम आधाररत ईांधन िे जलए सब्स्िीट्यूड् ईांधन िा जविास जिससे दहन िे
दौरान प्रदू षिोां िी िम िांसांिरेशन उत्‍पन्‍न होगी ।
(iii) हाजनरजहत गैसोां में प्रदू षिोां िो हिाने या जवद्यजित िरने िे जलए उत्‍सि‍न जनयांत्रि
उपिरिोां िो िोड़ना ।

Answer any 3 out of the given 5 questions in 50 – 80 words each. 34=12

20. Various main parts of commonly used Car Washer : 4
(i) Electric Motor
(ii) Reciprocating Water Pump
(iii) Water Tank
(iv) Spray Nozzle
(v) Flexible Water Pipe
(vi) Control Valve
(vii) Safety Valve
(viii) V Belt and Pulley
(ix) Pressure gauge
(i) इलेस्प्ररि मोिर
(ii) रे जसप्रोिेजिां ग वािर पांप
(iii) वािर िैं ि
(iv) स्‍प्रे नोिल
(v) फ्लेस्प्क्सबल वािर पाइप
(vi) िन्‍िर ोल वाल्‍व
(vii) सेफ्टी वाल्‍व
(viii) वी बेल्‍ि और पुली
(ix) प्रेशर गेि

21. Working Principle of Hydraulic Power Steering System in Neutral (Straight ahead
Position) : 4
Fluid from the pump is sent to the control valve. If the control valve is in the neutral
position, the fluid will flow through the control valve into the relief port and back to
the pump. At this time hardly any pressure is created and because the pressure on the
cylinder piston is equal on both sides, the piston will not move in either direction.

328 9 P.T.O.

While Turning : When the steering main shaft is turned in either direction, the
control valve also moves, closing one of the fluid passages.
फ्लूइड् िो पांप से जनयांत्रि वाल्‍व में भेिा िाता है । यजद जनयांत्रि वाल्‍व न्‍यूिरल पॉिीशन में है ,
तो फ्लूइि द्रव जनयांत्रि वाल्‍व िे माध्‍यम से ररलीि पोि‍ में प्रवाजहत होगा । इस समय शायद
ही िोई दबाव बनता है और क्‍योांजि जसलेंड्र जपस्‍िन पर दबाव दोनोां तरि बराबर होता है ,
जपस्‍िन जिसी भी जदशा में नहीां चलेगा ।
िन‍ लेते समय :
िब स्‍िीयररां ग मुख्‍य शॉफ्ट िो जिसी भी जदशा में घु माया िाता है , तो जनयांत्रि वाल्‍व भी
फ्लूइड् पैसेिज़ में से एि िो बांद िर दे ता है ।

22. Classification of Suspension Springs 4

Metallic Springs

Torsion Bar Spring :
A torsion bar spring is a spring steel rod that uses its torsional elasticity to resist
twisting. One end of the torsional bar spring is anchored to the frame or other
structural member of the body and other end to suspension arm, that is subjected to
torsional load.

नॉन-मैिेजलि्‍
स्प्रांग

िॉइ िॉश‍ हाइड्रोजलि्‍स्प्रांग
िॉश‍न बार स्प्रांग : ल न
328 10 P.T.O.

िॉश‍न बार स्प्रांग एि स्प्रांग स्‍िील रॉड् है , िो घुमाव िा जवरोध िरने िे जलए अपनी िॉश‍नल
इलास्प्िजसिी (लोच) िा उपयोग िरता है , िाश‍न बार िा एि जसरा या बॉड्ी िे अन्‍य
िर िचरल मैम्‍बर से िुड़ा होता है और दू सरा जसरा सस्‍पेंशन आम‍ से िुड़ा होता है िो मरोड़
वाले भार िे अधीन होता है ।

23. Defect — Transmission is noisy in neutral speed: any 4 4

Probable Causes Remedies
(i) Worn-out bearing – Replace the bearing
(ii) Lack of lubrication on – Lubricate bearing
bearing
(iii) Worn-out gear, broken – Replace damaged gears
or chipped teeth
(iv) Worn-out countershaft – Replace worn-out parts
(v) Bent or damaged – Replace damage parts
countershaft

दोष — िर ाां सजमशन िे न्‍यूिरल पॉिीशन में शोर होना :
(i) जबयररां ग में जघसाव होना – जबयररां ग बदजलए
(ii) जबयररां ग में लुब्रीिेशन – जबयररां ग िे लुब्रीिेि िीजिए
िा अभाव
(iii) जघसे हए जगयर, िू िा – क्षजतग्रस्‍त जगयर िो बदले
हआ या िू िे हए दााँ त
(iv) जघसा हआ – जघसे हए शाफ्ट िो बदले
िाउन्‍िरशाफ्ट
(v) मुड़ा हआ या क्षजतग्रस्‍त – क्षजतग्रस्‍त पाि्‍ स िो बदले
िाउन्‍िर शॉफ्ट

24. Various Purposes of Automotive Electrical System: 4
The auto electrical system has various electrical equipment’s and wires and serves
the following purposes.
(i) to generate the electricity for charging of battery.
(ii) to supply current to starting motor for cranking the engine.
(iii) to change the battery and supply the current to various units of an
automobile.
(iv) to supply the current to the lighting system for operation of headlights, brake
lights, flashers, fog lights, dippers, direction indicators, etc.
ऑिोइलैस्प्ररि जसस्‍िम में जवजभन्‍न जवद् युत उपिरि और तार होते है और जनम्‍नजलस्प्ित
उद्दे श्‍योां िो पूरा िरते हैं

328 11 P.T.O.

(i) बैिरी चाजििंग िे जलए इलेस्प्ररजसिी उत्‍पन्‍न िरना
(ii) इां िन िाि‍ िरने िे जलए स्‍िारिर मोिर िो िरां ि सप्‍लाई िरना
(iii) मोिर वाहन िे जवजभन्‍न पािों िो जवद् युत सप्‍लाई प्रदान िरना
(iv) हे ड्लाइि् स, ब्रेि लाइि् स, फ्लैशस‍ , िॉग लाइि् स, जड्प्‍पस‍ , जदशा सांिेति आजद िे
सांचालन िे जलए प्रिाश व्‍यवस्‍था िो िरां ि आपूजत‍ िरना ।

328 12 P.T.O.