Question
Download Solution PDFA filament lamp of 40 W, 110 V is connected in series with resistance R. If the supply voltage is 230 V, the value of resistance R should be:
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept
According to the KVL, the total voltage drop in a closed circuit is zero.
ΣV = 0
By Ohm's Law, the value of resistance is given by:
\(R={V\over I}\)
Calculation
The voltage across the resistance (R) is given by:
VR = 230 - 110 V = 120 V
The current across the bulb is given by:
\(I={P\over V}\)
\(I={40\over 110}={4\over 11}A\)
Since the bulb and resistance are in series, the current across both of them will be the same.
The value of R is given by:
\(R={120\over 4/11}\)
\(R={120\times 11\over 4}=330 \Omega \)
Last updated on May 8, 2025
-> The KVS TGT Notiifcation 2025 will be released for 16661 vacancies.
-> The application dates will be announced along with the official notification.
-> Graduates with B.Ed or an equivalent qualification are eligible for this post.
-> Prepare with the KVS TGT Previous Year Papers here.