Electronic

Question 5:Figure 3 shows an electronic circuit used to study the function of a npn transistor in the circuit. Readings IB and IC are obtained from microammeter, A1 and miliameter A2 respectively. The rheostat is adjusted to obtain different values of IB and IC as shown in Table 2.(a) Plot the graph of IC against IB.(b) Based on your … Read more

Question 3:Figure 2 shows a full-wave rectification kit connected to an alternating current power supply and a cathode ray oscilloscope.(a) draw arrows to show the flow of current through the diode during the positive half cycle and the negative half cycle.(b) Sketch what is displayed on the cathode ray oscilloscope screen if a capacitor is … Read more

Question 1:(a) Using appropriate electronic symbols, draw a forward biased semiconductor diode in an electronic circuit.(b) What will happen if the battery connection in 1(a) is reversed? Answer:(a)(b) The bulb does not light up because the diode is a in reverse biased state. Question 2:Figure 1 shows a half-wave rectification kit connected to an alternating … Read more

Question 1:Figure 5.20 shows the symbol for an electronic device.(a) What is the name of the electronic device?(b) What is the function of terminal X on the electronic device? Answer:(a) pnp transistor(b) Supply charge carriers to the collector Question 2:Figure 5.21 shows a transistor circuit which consists of two circuits, namely circuits A and B. … Read more

Question 1:What is the meaning of the following terms?(a) Semiconductor diode(b) Forward biased(c) Rectification Answer:(a) An electronic component which allows electric current to flow in one direction only.(b) A situation when the positive terminal of a dry cell is connected to the anode of diode and the negative terminal is connected to the cathode of … Read more

Question 1:(a) What are thermionic emission and cathode rays?(b) State the characteristics of cathode rays. Answer:(a) Thermionic emission is the emission of electrons from a heated metallic surface. The cathode rays are high speed electron beams in a vacuum tube.(b) Cathode rays are negatively charged, possess momentum and kinetic energy, move in straight lines and … Read more

Question 1:(a) What are thermionic emission and cathode rays?(b) State the characteristics of cathode rays. Answer:(a)Thermionic emission is the emission of electrons from a heated metallic surface. The cathode rays are high speed electron beams in a vacuum tube.(b)Cathode rays are negatively charged, possess momentum and kinetic energy, move in straight lines and can be … Read more

Diagram (4.1) shows a bright spot, P, formed on the screen of a cathode-ray oscilloscope, C.R.O. when it is switched on. What is the meaning of cathode ray? [1 mark] Explain how the bright spot is formed on the screen of the C.R.O. [2marks] Diagram (4.2) shows the bright spot is displaced to (Q) when … Read more

Logic gates can be combined together to perform certain tasks. The output can be determined by constructing a truth table. Example 1: In the combination of logic gates above, find the outputs X, Y and Z of the inputs A and B.Answer: INPUT OUTPUT A B X Y Z 0 0 1 1 1 0 … Read more