CBSE Class 12 Physics Question Paper 2013 (Delhi Set 1)

CBSE CLASS XII Questions

• 1.

  Two air-filled capacitors of capacitances $C_1$ and $C_2$ are connected in parallel with a dc battery. After the capacitors are fully charged, a slab of dielectric constant K is inserted between the plates of each capacitor. How will the (i) charge on each capacitor and (ii) energy stored in the capacitor affected after the slab is introduced.
  

  View Solution

  ---

• 2.

  A student sets up the circuit as shown in the figure to find the value of unknown resistance X and records a set of readings of the voltmeter and the ammeter by using the rheostat.
  

  

  ---

• 3.

  Write two advantages of reflecting telescope over refracting telescope.
  

  View Solution

  ---

• 4.

  The resistance of a metal wire at \( 20^\circ \text{C} \) is \( 1.05 \, \Omega \) and at \( 100^\circ \text{C} \) is \( 1.38 \, \Omega \). Determine the temperature coefficient of resistivity of this metal.

  View Solution

  ---

• 5.

  Two metal spheres of radii $r_1$ and $r_2$ ($> r_1$) having charges $q_1$ and $q_2$ respectively kept in air, are brought in contact. Which of the following statements is not correct ?
  

  • The total charge of the two spheres is conserved.
    
  • Both spheres attain the same potential.
    
  • The final potential of the system equals $\frac{1}{4\pi\epsilon_0} \frac{(q_1 + q_2)}{(r_1 + r_2)}$
    
  • The final potential of the system equals $\frac{1}{4\pi\epsilon_0} \frac{(q_1 + q_2) (r_1 + r_2)}{r_1 r_2}$
    
  View Solution

  ---

• 6.

  Derive an expression for the capacitance of a parallel plate capacitor of plate area A and plate separation d with air present between the plates.
  

  View Solution