1. Two capacitors of capacitances 2F and 4Fare charged to potential differences 10 V and 20 V, respectively. Find heat generated when they are connected together in such a way what positively charged plate of one is connected to the negatively charged plate of the other and vice versa. (A) 67 J (B) 300 J (C) 600 J (D) 900 J 2. The value of acceleration due to gravity at a height h(h < < < R) from the surface of earth is 3% less than its value at earth's surface. While at a depth d below the surface of earth it is 1% less than its value at earth's surface. The ratio (2) equals : (R: Radius of earth) (A) 1:3 (B) 3:2 (C) 6:1 (D) 2:3 3. In a resonance tube experiment when the tube is filled with water up to a height of 22.0 cm from bottom, it resonates with a given tuning fork. When the water level is raised, the next resonance with the same tuning fork occurs at a height of 32.0 cm. If the frequency of tuning fork is 1615 Hz, then the velocity of sound in air is : (A) 320 m/s (B) 321 m/s (C) 322 m/s (D) 323 m/s 4. Assume that the displacement(s) of air is proportional to the pressure difference (Ap) created by a sound wave. Displacement(s) further depends on the speed of sound (v), density of air (p) and the frequency (f). If Ap = 100Pa, v = 330 m/s, p = 1 kg/m and s = 10 mm, then frequency f will be of the order of (take the multiplicative constant to be 1) (A) 30 Hz (B) 300 Hz (C) 3000 Hz (D) None of these 5. An electrical power line delivers 1.1 kW at 220 V. If the efficiency of transmission is 90%, the total line resistance is close to : () 49 () 4.9 (C) 44 (D) 4.4