Class 12 Physics: CBSE Sample Question Paper (2024-25) | Sample Papers for Class 12 Medical and Non-Medical PDF Download

 Page 1


SAMPLE QUESTION PAPER  
PHYSICS 
Subject Code – 042  
CLASS – XII  
Academic Session 2024 – 25   
 
Maximum Marks: 70                          Time Allowed: 3 hours 
General Instructions 
 
(1) There are 33 questions in all. All questions are compulsory. 
(2) This question paper has five sections: Section A, Section B, Section C, Section D and Section E.  
(3) All the sections are compulsory. 
(4) Section A contains sixteen questions, twelve MCQ and four Assertion Reasoning based of 1 mark 
each, Section B contains five questions of two marks each, Section C contains seven questions of 
three marks each, Section D contains two case study-based questions of four marks each and 
Section E contains three long answer questions of five marks each.  
(5) There is no overall choice. However, an internal choice has been provided in one question in Section 
B, one question in Section C, one question in each CBQ in Section D and all three questions in 
Section E. You have to attempt only one of the choices in such questions. 
(6) Use of calculators is not allowed. 
(7) You may use the following values of physical constants where ever necessary 
i. c = 3 x 10
8 
m/s  
ii. me = 9.1 x10
-31 
kg 
iii. mp = 1.7 x10
-27
 kg  
iv. e = 1.6 x 10
-19
 C 
v. µ0 = 4p x 10
-7
 T m ?? -?? 
vi. h = 6.63 x10
-34
 J s 
vii. e0 = 8.854 x10
-12
 ?? ?? ?? -?? ?? -?? 
viii. Avogadro’s number = 6.023 X ????
????
 per gram mole 
                                                                              
Page 2


SAMPLE QUESTION PAPER  
PHYSICS 
Subject Code – 042  
CLASS – XII  
Academic Session 2024 – 25   
 
Maximum Marks: 70                          Time Allowed: 3 hours 
General Instructions 
 
(1) There are 33 questions in all. All questions are compulsory. 
(2) This question paper has five sections: Section A, Section B, Section C, Section D and Section E.  
(3) All the sections are compulsory. 
(4) Section A contains sixteen questions, twelve MCQ and four Assertion Reasoning based of 1 mark 
each, Section B contains five questions of two marks each, Section C contains seven questions of 
three marks each, Section D contains two case study-based questions of four marks each and 
Section E contains three long answer questions of five marks each.  
(5) There is no overall choice. However, an internal choice has been provided in one question in Section 
B, one question in Section C, one question in each CBQ in Section D and all three questions in 
Section E. You have to attempt only one of the choices in such questions. 
(6) Use of calculators is not allowed. 
(7) You may use the following values of physical constants where ever necessary 
i. c = 3 x 10
8 
m/s  
ii. me = 9.1 x10
-31 
kg 
iii. mp = 1.7 x10
-27
 kg  
iv. e = 1.6 x 10
-19
 C 
v. µ0 = 4p x 10
-7
 T m ?? -?? 
vi. h = 6.63 x10
-34
 J s 
vii. e0 = 8.854 x10
-12
 ?? ?? ?? -?? ?? -?? 
viii. Avogadro’s number = 6.023 X ????
????
 per gram mole 
                                                                              
                                                       [SECTION – A]                (16x1=16 marks) 
 
Q1. A uniform electric field pointing in positive X-direction exists in a region. Let A be the origin, B be the 
point on the X-axis at x = +1 cm and C be the point on the Y-axis at y = +1 cm. Then the potential at 
points A, B and C satisfy. 
 (A) V A < VB                (B) VA > VB.                    (C) V A < VC           (D) V A > VC 
 
Q2. A conducting wire connects two charged conducting spheres of radii r1 and r2 such that they attain 
equilibrium with respect to each other. The distance of separation between the two spheres is very large 
as compared to either of their radii. 
      The ratio of the magnitudes of the electric fields at the surfaces of the spheres of radii r1 and r2 is 
         (A) 
?? 1
?? 2
                        (B)  
?? 2
?? 1
                           (C)  
?? 2
2
?? 1
2
                             (D)  
?? 1
2
?? 2
2
 
 
Q3. A long straight wire of circular cross section of radius ?a? carries a steady current I. The current is 
uniformly distributed across its cross section. The ratio of magnitudes of the magnetic field at a point 
a/2 above the surface of wire to that of a point a/2 below its surface is 
(A)    4:1                   (B)   1:1                     (C)  4: 3                          (D)  3 :4 
Q4. The diffraction effect can be observed in 
(A)  sound waves only       (B)  light waves only  
(C)  ultrasonic waves only     (D) sound waves as well as light waves 
 
Q5. A capacitor consists of two parallel plates, with an area of cross-section of 0.001 m
2
, separated by a 
distance of 0.0001 m. If the voltage across the plates varies at the rate of 10
8
 V/s, then the value of 
displacement current through the capacitor is 
       (A) 8.85 × 10
-3
??     (B) 8.85 × 10
-4
??       (C) 7.85 × 10
-3
??             (D) 9.85 × 10
-3
?? 
Q6. In a series LCR circuit, the voltage across the resistance, capacitance and inductance is 10 V each. If 
the capacitance is short circuited the voltage across the inductance will be 
 (A) 10 V                  (B) 10v2  V               (C) 10/v2  V                 (D) 20 V 
 
Page 3


SAMPLE QUESTION PAPER  
PHYSICS 
Subject Code – 042  
CLASS – XII  
Academic Session 2024 – 25   
 
Maximum Marks: 70                          Time Allowed: 3 hours 
General Instructions 
 
(1) There are 33 questions in all. All questions are compulsory. 
(2) This question paper has five sections: Section A, Section B, Section C, Section D and Section E.  
(3) All the sections are compulsory. 
(4) Section A contains sixteen questions, twelve MCQ and four Assertion Reasoning based of 1 mark 
each, Section B contains five questions of two marks each, Section C contains seven questions of 
three marks each, Section D contains two case study-based questions of four marks each and 
Section E contains three long answer questions of five marks each.  
(5) There is no overall choice. However, an internal choice has been provided in one question in Section 
B, one question in Section C, one question in each CBQ in Section D and all three questions in 
Section E. You have to attempt only one of the choices in such questions. 
(6) Use of calculators is not allowed. 
(7) You may use the following values of physical constants where ever necessary 
i. c = 3 x 10
8 
m/s  
ii. me = 9.1 x10
-31 
kg 
iii. mp = 1.7 x10
-27
 kg  
iv. e = 1.6 x 10
-19
 C 
v. µ0 = 4p x 10
-7
 T m ?? -?? 
vi. h = 6.63 x10
-34
 J s 
vii. e0 = 8.854 x10
-12
 ?? ?? ?? -?? ?? -?? 
viii. Avogadro’s number = 6.023 X ????
????
 per gram mole 
                                                                              
                                                       [SECTION – A]                (16x1=16 marks) 
 
Q1. A uniform electric field pointing in positive X-direction exists in a region. Let A be the origin, B be the 
point on the X-axis at x = +1 cm and C be the point on the Y-axis at y = +1 cm. Then the potential at 
points A, B and C satisfy. 
 (A) V A < VB                (B) VA > VB.                    (C) V A < VC           (D) V A > VC 
 
Q2. A conducting wire connects two charged conducting spheres of radii r1 and r2 such that they attain 
equilibrium with respect to each other. The distance of separation between the two spheres is very large 
as compared to either of their radii. 
      The ratio of the magnitudes of the electric fields at the surfaces of the spheres of radii r1 and r2 is 
         (A) 
?? 1
?? 2
                        (B)  
?? 2
?? 1
                           (C)  
?? 2
2
?? 1
2
                             (D)  
?? 1
2
?? 2
2
 
 
Q3. A long straight wire of circular cross section of radius ?a? carries a steady current I. The current is 
uniformly distributed across its cross section. The ratio of magnitudes of the magnetic field at a point 
a/2 above the surface of wire to that of a point a/2 below its surface is 
(A)    4:1                   (B)   1:1                     (C)  4: 3                          (D)  3 :4 
Q4. The diffraction effect can be observed in 
(A)  sound waves only       (B)  light waves only  
(C)  ultrasonic waves only     (D) sound waves as well as light waves 
 
Q5. A capacitor consists of two parallel plates, with an area of cross-section of 0.001 m
2
, separated by a 
distance of 0.0001 m. If the voltage across the plates varies at the rate of 10
8
 V/s, then the value of 
displacement current through the capacitor is 
       (A) 8.85 × 10
-3
??     (B) 8.85 × 10
-4
??       (C) 7.85 × 10
-3
??             (D) 9.85 × 10
-3
?? 
Q6. In a series LCR circuit, the voltage across the resistance, capacitance and inductance is 10 V each. If 
the capacitance is short circuited the voltage across the inductance will be 
 (A) 10 V                  (B) 10v2  V               (C) 10/v2  V                 (D) 20 V 
 
 Q7. Correct match of column I with column II is 
C-l (waves) C-ll (Production) 
(1) Infra-red  P . Rapid vibration of electrons in aerials 
(2) Radio Q . Electrons in atoms emit light when they move from higher to 
lower energy level. 
(3) Light R . Klystron valve 
(4) Microwave S . Vibration of atoms and molecules 
 
              (A) 1-P, 2-R, 3-S, 4-Q    (B) 1-S, 2-P, 3-O, 4-R 
              (C) 1-Q, 2-P, 3-S, 4-R                                  (D) 1-S. 2-R, 3-P, 4-Q  
 
Q8. The distance of closest approach of an alpha particle is d when it moves with a speed V towards a 
nucleus. 
 Another alpha particle is projected with higher energy such that the new distance of the closest 
approach is d/2. What is the speed of projection of the alpha particle in this case? 
         (A) V /2                      (B) v2 V                      (C) 2 V                          (D) 4 V 
 
 Q9. A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The                  
distance of virtual image from the surface of the sphere is    
 (A) 2 cm                     (B) 4 cm                      (C) 6 cm                        (D) 12 cm 
Q10. Colours observed on a CD (Compact Disk) is due to 
          (A) Reflection         (B) Diffraction          (C) Dispersion              (D) Absorption 
 
 Q11. The number of electrons made available for conduction by dopant atoms depends strongly upon    
(A) doping level                                                    (B) increase in ambient temperature  
         (C) energy gap                                                    (D) options (A) and (B) both 
 
 Q12. If copper wire is stretched to make its radius decrease by 0.1%, then the percentage change in its        
resistance is approximately 
Page 4


SAMPLE QUESTION PAPER  
PHYSICS 
Subject Code – 042  
CLASS – XII  
Academic Session 2024 – 25   
 
Maximum Marks: 70                          Time Allowed: 3 hours 
General Instructions 
 
(1) There are 33 questions in all. All questions are compulsory. 
(2) This question paper has five sections: Section A, Section B, Section C, Section D and Section E.  
(3) All the sections are compulsory. 
(4) Section A contains sixteen questions, twelve MCQ and four Assertion Reasoning based of 1 mark 
each, Section B contains five questions of two marks each, Section C contains seven questions of 
three marks each, Section D contains two case study-based questions of four marks each and 
Section E contains three long answer questions of five marks each.  
(5) There is no overall choice. However, an internal choice has been provided in one question in Section 
B, one question in Section C, one question in each CBQ in Section D and all three questions in 
Section E. You have to attempt only one of the choices in such questions. 
(6) Use of calculators is not allowed. 
(7) You may use the following values of physical constants where ever necessary 
i. c = 3 x 10
8 
m/s  
ii. me = 9.1 x10
-31 
kg 
iii. mp = 1.7 x10
-27
 kg  
iv. e = 1.6 x 10
-19
 C 
v. µ0 = 4p x 10
-7
 T m ?? -?? 
vi. h = 6.63 x10
-34
 J s 
vii. e0 = 8.854 x10
-12
 ?? ?? ?? -?? ?? -?? 
viii. Avogadro’s number = 6.023 X ????
????
 per gram mole 
                                                                              
                                                       [SECTION – A]                (16x1=16 marks) 
 
Q1. A uniform electric field pointing in positive X-direction exists in a region. Let A be the origin, B be the 
point on the X-axis at x = +1 cm and C be the point on the Y-axis at y = +1 cm. Then the potential at 
points A, B and C satisfy. 
 (A) V A < VB                (B) VA > VB.                    (C) V A < VC           (D) V A > VC 
 
Q2. A conducting wire connects two charged conducting spheres of radii r1 and r2 such that they attain 
equilibrium with respect to each other. The distance of separation between the two spheres is very large 
as compared to either of their radii. 
      The ratio of the magnitudes of the electric fields at the surfaces of the spheres of radii r1 and r2 is 
         (A) 
?? 1
?? 2
                        (B)  
?? 2
?? 1
                           (C)  
?? 2
2
?? 1
2
                             (D)  
?? 1
2
?? 2
2
 
 
Q3. A long straight wire of circular cross section of radius ?a? carries a steady current I. The current is 
uniformly distributed across its cross section. The ratio of magnitudes of the magnetic field at a point 
a/2 above the surface of wire to that of a point a/2 below its surface is 
(A)    4:1                   (B)   1:1                     (C)  4: 3                          (D)  3 :4 
Q4. The diffraction effect can be observed in 
(A)  sound waves only       (B)  light waves only  
(C)  ultrasonic waves only     (D) sound waves as well as light waves 
 
Q5. A capacitor consists of two parallel plates, with an area of cross-section of 0.001 m
2
, separated by a 
distance of 0.0001 m. If the voltage across the plates varies at the rate of 10
8
 V/s, then the value of 
displacement current through the capacitor is 
       (A) 8.85 × 10
-3
??     (B) 8.85 × 10
-4
??       (C) 7.85 × 10
-3
??             (D) 9.85 × 10
-3
?? 
Q6. In a series LCR circuit, the voltage across the resistance, capacitance and inductance is 10 V each. If 
the capacitance is short circuited the voltage across the inductance will be 
 (A) 10 V                  (B) 10v2  V               (C) 10/v2  V                 (D) 20 V 
 
 Q7. Correct match of column I with column II is 
C-l (waves) C-ll (Production) 
(1) Infra-red  P . Rapid vibration of electrons in aerials 
(2) Radio Q . Electrons in atoms emit light when they move from higher to 
lower energy level. 
(3) Light R . Klystron valve 
(4) Microwave S . Vibration of atoms and molecules 
 
              (A) 1-P, 2-R, 3-S, 4-Q    (B) 1-S, 2-P, 3-O, 4-R 
              (C) 1-Q, 2-P, 3-S, 4-R                                  (D) 1-S. 2-R, 3-P, 4-Q  
 
Q8. The distance of closest approach of an alpha particle is d when it moves with a speed V towards a 
nucleus. 
 Another alpha particle is projected with higher energy such that the new distance of the closest 
approach is d/2. What is the speed of projection of the alpha particle in this case? 
         (A) V /2                      (B) v2 V                      (C) 2 V                          (D) 4 V 
 
 Q9. A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The                  
distance of virtual image from the surface of the sphere is    
 (A) 2 cm                     (B) 4 cm                      (C) 6 cm                        (D) 12 cm 
Q10. Colours observed on a CD (Compact Disk) is due to 
          (A) Reflection         (B) Diffraction          (C) Dispersion              (D) Absorption 
 
 Q11. The number of electrons made available for conduction by dopant atoms depends strongly upon    
(A) doping level                                                    (B) increase in ambient temperature  
         (C) energy gap                                                    (D) options (A) and (B) both 
 
 Q12. If copper wire is stretched to make its radius decrease by 0.1%, then the percentage change in its        
resistance is approximately 
(A) –0.4%               (B) +0.8%                    (C) +0.4%            (D) +0.2%                                   
 
For Questions 13 to 16, two statements are given –one labelled Assertion (A) and other labelled 
Reason (R). Select the correct answer to these questions from the options as given below. 
A.  If both Assertion and Reason are true and Reason is the correct explanation of Assertion. 
B.  If both Assertion and Reason are true but Reason is not the correct explanation of Assertion. 
C. If Assertion is true but Reason is false. 
D. If both Assertion and Reason are false. 
 Q13.  Assertion (A): On increasing the current sensitivity of a galvanometer by increasing the number of 
turns may not necessarily increase its voltage sensitivity.  
Reason(R) : The resistance of the coil of the galvanometer increases on increasing the number of 
turns. 
 
 Q14.   Assertion (A): In a hydrogen atom there is only one electron but its emission spectrum shows many   
lines.  
Reason (R): In a given sample of hydrogen there are many atoms each containing one electron; 
hence many electrons in different atoms may be in different orbits so many transitions from higher 
to lower orbits are possible.    
   
      Q15.  Assertion (A): Nuclei having mass number about 60 are least stable.. 
    Reason (R): When two or more light nuclei are combined into a heavier nucleus then the binding 
energy per nucleon will decrease. 
  Q16.  Assertion (A): de Broglie's wavelength of a freely falling body keeps decreasing with time. 
   Reason (R): The momentum of the freely falling body increases with time. 
 
[SECTION – B]                                (05x2=10 marks) 
   Q17. A platinum surface having work function 5.63 eV is illuminated by a monochromatic source of 1.6 
x 10 
15
 Hz. What will be the minimum wavelength associated with the ejected electron. 
 
Page 5


SAMPLE QUESTION PAPER  
PHYSICS 
Subject Code – 042  
CLASS – XII  
Academic Session 2024 – 25   
 
Maximum Marks: 70                          Time Allowed: 3 hours 
General Instructions 
 
(1) There are 33 questions in all. All questions are compulsory. 
(2) This question paper has five sections: Section A, Section B, Section C, Section D and Section E.  
(3) All the sections are compulsory. 
(4) Section A contains sixteen questions, twelve MCQ and four Assertion Reasoning based of 1 mark 
each, Section B contains five questions of two marks each, Section C contains seven questions of 
three marks each, Section D contains two case study-based questions of four marks each and 
Section E contains three long answer questions of five marks each.  
(5) There is no overall choice. However, an internal choice has been provided in one question in Section 
B, one question in Section C, one question in each CBQ in Section D and all three questions in 
Section E. You have to attempt only one of the choices in such questions. 
(6) Use of calculators is not allowed. 
(7) You may use the following values of physical constants where ever necessary 
i. c = 3 x 10
8 
m/s  
ii. me = 9.1 x10
-31 
kg 
iii. mp = 1.7 x10
-27
 kg  
iv. e = 1.6 x 10
-19
 C 
v. µ0 = 4p x 10
-7
 T m ?? -?? 
vi. h = 6.63 x10
-34
 J s 
vii. e0 = 8.854 x10
-12
 ?? ?? ?? -?? ?? -?? 
viii. Avogadro’s number = 6.023 X ????
????
 per gram mole 
                                                                              
                                                       [SECTION – A]                (16x1=16 marks) 
 
Q1. A uniform electric field pointing in positive X-direction exists in a region. Let A be the origin, B be the 
point on the X-axis at x = +1 cm and C be the point on the Y-axis at y = +1 cm. Then the potential at 
points A, B and C satisfy. 
 (A) V A < VB                (B) VA > VB.                    (C) V A < VC           (D) V A > VC 
 
Q2. A conducting wire connects two charged conducting spheres of radii r1 and r2 such that they attain 
equilibrium with respect to each other. The distance of separation between the two spheres is very large 
as compared to either of their radii. 
      The ratio of the magnitudes of the electric fields at the surfaces of the spheres of radii r1 and r2 is 
         (A) 
?? 1
?? 2
                        (B)  
?? 2
?? 1
                           (C)  
?? 2
2
?? 1
2
                             (D)  
?? 1
2
?? 2
2
 
 
Q3. A long straight wire of circular cross section of radius ?a? carries a steady current I. The current is 
uniformly distributed across its cross section. The ratio of magnitudes of the magnetic field at a point 
a/2 above the surface of wire to that of a point a/2 below its surface is 
(A)    4:1                   (B)   1:1                     (C)  4: 3                          (D)  3 :4 
Q4. The diffraction effect can be observed in 
(A)  sound waves only       (B)  light waves only  
(C)  ultrasonic waves only     (D) sound waves as well as light waves 
 
Q5. A capacitor consists of two parallel plates, with an area of cross-section of 0.001 m
2
, separated by a 
distance of 0.0001 m. If the voltage across the plates varies at the rate of 10
8
 V/s, then the value of 
displacement current through the capacitor is 
       (A) 8.85 × 10
-3
??     (B) 8.85 × 10
-4
??       (C) 7.85 × 10
-3
??             (D) 9.85 × 10
-3
?? 
Q6. In a series LCR circuit, the voltage across the resistance, capacitance and inductance is 10 V each. If 
the capacitance is short circuited the voltage across the inductance will be 
 (A) 10 V                  (B) 10v2  V               (C) 10/v2  V                 (D) 20 V 
 
 Q7. Correct match of column I with column II is 
C-l (waves) C-ll (Production) 
(1) Infra-red  P . Rapid vibration of electrons in aerials 
(2) Radio Q . Electrons in atoms emit light when they move from higher to 
lower energy level. 
(3) Light R . Klystron valve 
(4) Microwave S . Vibration of atoms and molecules 
 
              (A) 1-P, 2-R, 3-S, 4-Q    (B) 1-S, 2-P, 3-O, 4-R 
              (C) 1-Q, 2-P, 3-S, 4-R                                  (D) 1-S. 2-R, 3-P, 4-Q  
 
Q8. The distance of closest approach of an alpha particle is d when it moves with a speed V towards a 
nucleus. 
 Another alpha particle is projected with higher energy such that the new distance of the closest 
approach is d/2. What is the speed of projection of the alpha particle in this case? 
         (A) V /2                      (B) v2 V                      (C) 2 V                          (D) 4 V 
 
 Q9. A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The                  
distance of virtual image from the surface of the sphere is    
 (A) 2 cm                     (B) 4 cm                      (C) 6 cm                        (D) 12 cm 
Q10. Colours observed on a CD (Compact Disk) is due to 
          (A) Reflection         (B) Diffraction          (C) Dispersion              (D) Absorption 
 
 Q11. The number of electrons made available for conduction by dopant atoms depends strongly upon    
(A) doping level                                                    (B) increase in ambient temperature  
         (C) energy gap                                                    (D) options (A) and (B) both 
 
 Q12. If copper wire is stretched to make its radius decrease by 0.1%, then the percentage change in its        
resistance is approximately 
(A) –0.4%               (B) +0.8%                    (C) +0.4%            (D) +0.2%                                   
 
For Questions 13 to 16, two statements are given –one labelled Assertion (A) and other labelled 
Reason (R). Select the correct answer to these questions from the options as given below. 
A.  If both Assertion and Reason are true and Reason is the correct explanation of Assertion. 
B.  If both Assertion and Reason are true but Reason is not the correct explanation of Assertion. 
C. If Assertion is true but Reason is false. 
D. If both Assertion and Reason are false. 
 Q13.  Assertion (A): On increasing the current sensitivity of a galvanometer by increasing the number of 
turns may not necessarily increase its voltage sensitivity.  
Reason(R) : The resistance of the coil of the galvanometer increases on increasing the number of 
turns. 
 
 Q14.   Assertion (A): In a hydrogen atom there is only one electron but its emission spectrum shows many   
lines.  
Reason (R): In a given sample of hydrogen there are many atoms each containing one electron; 
hence many electrons in different atoms may be in different orbits so many transitions from higher 
to lower orbits are possible.    
   
      Q15.  Assertion (A): Nuclei having mass number about 60 are least stable.. 
    Reason (R): When two or more light nuclei are combined into a heavier nucleus then the binding 
energy per nucleon will decrease. 
  Q16.  Assertion (A): de Broglie's wavelength of a freely falling body keeps decreasing with time. 
   Reason (R): The momentum of the freely falling body increases with time. 
 
[SECTION – B]                                (05x2=10 marks) 
   Q17. A platinum surface having work function 5.63 eV is illuminated by a monochromatic source of 1.6 
x 10 
15
 Hz. What will be the minimum wavelength associated with the ejected electron. 
 
   Q18. (I)  A beam of light consisting of two wavelengths, 4000 Å and 6000 Å, is used to obtain 
interference fringes in a Young’s double-slit experiment. What is the least distance from the 
central maximum where the dark fringe is obtained? 
                                                                               OR 
             (II) In Young’s double-slit experiment using monochromatic light of wavelength ?, the intensities 
of two sources are I. What is the intensity of light at a point where path difference between 
wavefronts is ?/4? 
 
 
 Q19. P and Q are two identical charged particles each of mass 4 × 10
–26
 kg and charge 4.8 × 10
–19
 C, 
each moving with the same speed of 2.4 × 10
5
 m/s as shown in the figure. The two particles are 
equidistant (0.5 m) from the vertical Y -axis. At some instant, a magnetic field B is switched on so 
that the two particles undergo head-on collision. 
 
                                  
           Find –   
(I) the direction of the magnetic field and  
(II) the magnitude of the magnetic field applied in the region. 
 
(for VI candidates) 
A proton is moving with speed of 2 x 10
5
 m s
–1
 enters a uniform magnetic field B = 1.5 T. At the 
entry velocity vector makes an angle of 30° to the direction of the magnetic field. Calculate  
(a) the pitch of helical path described by the charge 
(b) Kinetic energy after completing half of the circle. 
 
Q.20. Binding energy per nucleon vs mass number curve for nuclei is shown in the figure. W, X, Y and Z 
are four nuclei indicated on the curve. Identify which of the following nuclei is most likely to undergo 
         (i) Nuclear Fission