4. A wave of frequency of 10 kHz and amplitude 20 volts is being used to modulate amplitude of carrier wave of frequency 1000 kHz and peak voltage 40 volts. Choose correct option regarding carrier modulated wave. (a) Equation of carrier modulated wave is 40{1+0.25 sin 2010t} sin(210) and modulation index is 0.2 (b) Equation of carrier modulated wave is 40{1+0.5 sin 20x10't} sin(2x10ft) and modulation index is 0.5 (c) Equation of carrier modulated wave is 40{1+0.5 sin 20x10t) sin(2x10t) and modulation index is 2 (d) Equation of carrier modulated wave is 401+0.5 sin 2010t} sin(2x10t) and depth of modulation is 0.5 5. A composite rod made up of two conductors of resistivity P, and p2 is show in the figure. If face A and B are connected to a battery, find the resistance of the rod. P2. Pi L 2a (a) (P,+P)L 4a (b) (3p+p)L B 2a PIP,L a(3p, +P) (d) 3pipL a (3p,+P2) 6. A point source surrounded by vacuum emits an electromagnetic wave of frequency of 900 kHz. If the power emitted by the source is 15 W, the amplitude of the electric field of the wave (in 10-3 V/m) at a distance 15 km from the source is: 1 Nm 910 C and speed of light in vacuum = 3 x 108 ms ) (a) 2 (b) 4 (c) 20 (d) 40