iGCSE Physics (0625) 4.3.3 Action and use of circuit components-Exam Style Questions- New Syllabus
▶️ Answer/Explanation
Detailed solution:
As the thermistor is heated, its resistance R th decreases because it is an NTC (negative temperature coefficient) component. Since the components are in series, the total circuit resistance R total =R+R th decreases, which causes the circuit current I to increase according to I= R total V supply , leading to a higher ammeter reading. The voltmeter is connected across the fixed resistor R; as the current I increases, the potential difference across it, V=I×R, must also increase. Consequently, both the ammeter and voltmeter readings increase, making option D the correct choice.
Question
What is a thermistor?
A) a container to keep a hot liquid warm
B) a circuit to control room temperature
C) a temperature-dependent resistor
D) a heater for a room
▶️Answer/Explanation
Ans: C
Questions
A transformer has 400 turns on the primary coil connected to the 240V mains supply. There are two secondary coils to serve different parts of a television. Secondary coil 1 has 2500 turns and secondary coil 2 has 20 turns. Which row is correct?
▶️Answer/Explanation
Ans B