CBSE Class 12 Physics Question Paper 2005 (3)

CBSE Class 12 Physics Question Paper 2005 (3). Students can download the last year question papers using the link below. Free download of examination question papers with solutions.Last 10 year question papers should be practised to get better marks in examinations.

Q1. An electrostatic field line cannot be discontinuous. Why?

Q2. Two wires of equal lengths are bent in the form of two loops. One of the loops is square shaped whereas the other loop is circular. These are suspended in a uniform magnetic field and the same current is passed through them. Which loop will experience greater torque? Give reasons. 

Q3. A bulb and a capacitor are connected in series to an a.c. source of variable frequency. How will the brightness of the bulb change on increasing the frequency of the a.c. source? Give reason. 

Q4. Ultraviolet light is incident on two photosensitive materials having work functions W1 and W2 (W1 > W2), in which case will the kinetic energy of the emitted electrons be greater? Why?

Q5. What is the function of cladding' in a typical optical fiber?

Q6. Define electric field intensity. Write its S. l unit. Write the magnitude and direction of electric field intensity due to an electric dipole of length 2a at the mid- point of the tine joining the two charges. 

Q7. A parallel capacitor is to be designed with a voltage rating 1 kV using a material of dielectric constant 3 and 4ickeclric strength about 10 7 Vm -1 . For safety we would like the field never to exceed say, 10% of the dipole strength. What minimum area of the plats is required to have a capacitance of 50 PF?

Q8. How does the receptivity of (i) a conductor and (ii) a semiconductor vary with temperature? Give reason for each case. 

Q9. Write two characteristic properties to distinguish between diamagnetic and paramagnetic  materials. 

Q10. A circular coil of radius 8 cm and 20 turns rotates about its vertical diameter with an angular speed of 50 s-1 in a uniform horizontal magnetic field of magnitude 3 x 10-2 T. Find themaximum and average value of the emf induced in the coiL.

Please click the link below to download pdf file of CBSE Class 12 Physics Question Paper 2005 (3).