Subject

Physics

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.

 Multiple Choice QuestionsShort Answer Type

1.

Write the expression, in a vector form, for the Lorentz magnetic force straight F with rightwards harpoon with barb upwards on top due to a charge moving with velocity straight V with rightwards arrow on top  in a magnetic field B. What is the direction of the magnetic force?                 


Write the expression, in a vector form, for the Lorentz magnetic force straight F with rightwards harpoon with barb upwards on top due to a charge moving with velocity straight V with rightwards arrow on top  in a magnetic field B. What is the direction of the magnetic force?                 

1808 Views

2.

The carrier wave is given by C (t) = 2sin (8πt) Volt.
The modulating signal is a square wave as shown. Find modulation index. 


The carrier wave is given by C (t) = 2sin (8πt) Volt.
The modulating signal is a square wave as shown. Find modulation index. 

2277 Views

3.

A capacitor 'C', a variable resistor 'R' and a bulb 'B' are connected in series to the ac mains in circuit as shown. The bulb glows with some brightness. How will the glow of the bulb change if (i) a dielectric slab is introduced between the plates of the capacitor, keeping resistance R to be the same; (ii) the resistance R is increased keeping the same capacitance? 



A capacitor 'C', a variable resistor 'R' and a bulb 'B' are connected in series to the ac mains in circuit as shown. The bulb glows with some brightness. How will the glow of the bulb change if (i) a dielectric slab is introduced between the plates of the capacitor, keeping resistance R to be the same; (ii) the resistance R is increased keeping the same capacitance? 


1483 Views

4.

Two spherical bobs, one metallic and the other of glass, of the same size are allowed to fall freely from the same height above the ground. Which of the two would reach earlier and why?


Two spherical bobs, one metallic and the other of glass, of the same size are allowed to fall freely from the same height above the ground. Which of the two would reach earlier and why?

3773 Views

5.

"For any charge configuration, equipotential surface through a point is normal to the electric field." Justify. 


"For any charge configuration, equipotential surface through a point is normal to the electric field." Justify. 

2675 Views

6.

Out of the two magnetic materials, 'A' has relative permeability slightly greater than unity while 'B' has less than unity. Identify the nature of the materials 'A' and 'B'. Will their susceptibilities be positive or negative? 


Out of the two magnetic materials, 'A' has relative permeability slightly greater than unity while 'B' has less than unity. Identify the nature of the materials 'A' and 'B'. Will their susceptibilities be positive or negative? 

1703 Views

7.

Given a uniform electric field E =5 ×10straight i with hat on top N/C, find the flux of this field through a square of 10 cm on a side whose plane is parallel to the y-z plane. What would be the flux through the same square if the plane makes a 30° angle with the x-axis?                 


Given a uniform electric field E =5 ×10straight i with hat on top N/C, find the flux of this field through a square of 10 cm on a side whose plane is parallel to the y-z plane. What would be the flux through the same square if the plane makes a 30° angle with the x-axis?                 

4101 Views

8.

State Kirchhoff's rules. Explain briefly how these rules are justified.


State Kirchhoff's rules. Explain briefly how these rules are justified.

3510 Views

9.

Define the term 'Mobility' of charge carriers in a conductor. Write its S.I. unit              


Define the term 'Mobility' of charge carriers in a conductor. Write its S.I. unit              

5056 Views

10.

Show variation of resistivity of copper as a function of temperature in a graph. 


Show variation of resistivity of copper as a function of temperature in a graph. 

1275 Views