I Explain how to construct a NAND gate using Diode & Transistor. (2.5 Marks) II Explain the construction of (AB) + (CD)gate using NMOS and PMOS transistor. (2.5 Marks) III In a RC charging circuit, given R = 100 Kohm, Supply voltage = 12 V and voltage across the capacitor is 5.8 V after time t = 15 ms. Find the value of the capacitor used. (2.5 Marks) IV If R = 10 Kohm and C = 10 pF, find the frequency of the astable multivibrator? Draw its output waveform for Vcc=+5V. (2.5 Marks)