Class 12 Physics is a very important subject for plus two students and so they prepare ahead hoping to do well in the exams. They reach out to all resources ranging from textbooks to class notes, solution books, previous year question papers, model question papers etc so that they can study well and also get the practice to write the exams well. We at BYJU’s catering to this requirement have compiled some important questions for class 12 Kerala Board students.

We will see here also how the Kerala Plus Two Physics Important Questions can help students to prepare for the upcoming board exams. It gives students the confidence to write exams and also face the boards without fear. They gain more practice in solving the questions of physics. The important question papers are created on the basis of the Kerala Board Plus Two Physics syllabus, thus covering all the important topics and concepts taught in the subject.

### Download Kerala Board plus two Physics important Question PDF

Get here an overview of the important physics question for class 12 Kerala Board:

**1.** Two equal and opposite charges placed in air is as shown in figure:

(a)Redraw the figure and show the direction of the dipole moment (P), direction of the

resultant electric field (E) at P.

(b)Write an equation to find out the electric field at P.

**2**. What do you mean by drift velocity? Write a relation between drift velocity and electric current.

**3**. A galvanometer is connected as shown in the picture below:

- This combination can be used as ___________________( voltmeter/ rheostat/ ammeter)
- Derive an expression to find the value of resistance S.

**4.** The block diagram below shows the general form of a Communicative system

- Identify the blocks X and Y
- What is the difference between attenuation and amplification?

**5.** a Name the part of the electromagnetic spectrum:

- used in radar systems
- Produced by bombarding a metal target by a high speed electron

b Electromagnetic waves are produced by___________________

(charges at rest/ charges in uniform motion/ charges in accelerated motion)

c. Why only microwaves are used in microwave ovens?

**6**. Two thin convex lenses of focal length f₁ and f are placed in contact:

- If the object is at principal axis, draw Ray diagram of the image formation by this combination of lenses
- Obtain a general expression for effective focal length of the combination in terms of f₁ and f

**7.** (a) Derive an expression for self inductance of a solenoid

(b) What do you mean by eddy current? Write any two applications of it.

**8**. (a) Name the different series of line observed in a hydrogen spectrum

(b) Draw energy level diagram of hydrogen atom

**9**. Symbol of a diode is given below:

- The diode is a __________ (rectifier diode/ photo diode/ zener diode)
- Draw the VI characteristics of the above diode
- A zener diode with

= 6.0V is used for voltage regulation. The current through the load is to be 4.0mA and that through the zener diode is 20mA. If the unregulated output is 10.0V, what is the value of the series resistor R. - What is the fundamental frequency of the ripple in a full wave rectifier circuit operating from 50Hz mains?

**10.** Two spheres encloses charges as shown in the diagram below:

- Derive an expression of electric field intensity at any point on the surface S₂
- What is the ratio of the electric flux through Sand S₂.

**11.** (a) Choose the wrong option:

(i) Volt= Weber/ second (ii) Weber = Henry X Ampere

(iii) Joule= Henry X Ampere² (iv) Volt=Weber x Second

(b) The current in a coil of self- inductance 0.1 H varies from 2A to 5A in a time of 1ms. Find the induced emf across the coil.

**12.** (a) Sound waves do not exhibit_______

(i) interference (ii) diffraction (iii) Polarisation (iv) reflection

(b)Describe Young’s double slit experiment to determine the bandwidth of the interference pattern

Or

- The intensity of scattered light in Rayleigh scattering is proportional to __________
- Explain the diffraction pattern obtained due to a single slit and represent graphically the variation of intensity with angle of diffraction

**13.** Choose the appropriate values for x-rays from the below table:

Wavelength |
Frequency |

1mm | 3 x 10¹⁷ Hz |

1m | 3 x 10⁸ Hz |

1 nm | 3 x 10²¹ Hz |

**14.** (a) Define half life period of a radioactive nucleus. Write down the relation connecting half life period and mean life.

(b) Define 1 amu.Calculate its energy equivalent to MeV.

**15.** Write down the truth table of a NOR gate.

**16.** (a) The work function of a metal is 6 eV. If two photons each have energy 4 eV strike with the metal surface.

(i) will the emission be possible? (ii) why?

(b) The waves associated with the matter is called matter waves. Let and be the de-Broglie wavelengths associated with electron and proton respectively. If they are accelerated by the same potential, then

(i) > (ii) > (iii) (iv) ⁻= \(\frac{1}{\lambda _{p}}\)

**17.** (a) The core of the transformer has the following properties:

(i) Core is laminated (ii) hysteresis loop is narrow

Explain the significance of each property

(b) What is the significance of each property?

**18.** (a) List out any two limitations of Bohr atom model.

(b) According to de-Broglie’s explanation of Bohr’s second postulate of quantization, the standing particle wave on a circular orbit for n=4 is given by:

(i) \({2\pi r_{n}=4/\lambda}\)

(ii) \(\frac{2\pi }{\lambda }= 4r_{n}\)

(iii) \(2\pi r_{n}=4\lambda\)

(iv) \(\frac{\lambda }{2\pi}= 4r_{n}\)

**19.** (a) What do you mean by Q value of a nuclear reaction?

(b) Write down the expressions for Q value in the case of decay

(c) Two nuclei have mass numbers in the ratio 1:64. What is the ratio of their nuclear radii?

**20.** (a) State Gauss Law for Magnetism

(b) How this differs from Gauss law for electrostatics?

(c)Why is the difference in the two cases?