Example 1 · difficulty 4/5
A silicon diode with a knee (cut-in) voltage of 0.7 V is forward biased in series with a 90 Ω resistor across an ideal 5.0 V battery. The steady current in the circuit is closest to:
- A. 52 mA
- B. 56 mA
- C. 63 mA
- D. 48 mA
2018 source guide · Physics
NEET 2018 Physics Semiconductor Electronics Questions
Use this page to connect the official 2018 paper with current Physics practice. NeetVellum does not claim a chapter appeared in that paper until the official question and final key have been mapped.
What to master
junction diodes, rectification, logic gates and elementary devices.
Original practice preview
These are current-syllabus NeetVellum questions, shown separately from historical-paper provenance.
Example 2 · difficulty 1/5
Which energy-band description best explains the high electrical conductivity of a metal?
- A. Its highest occupied band is partially filled, or it overlaps the next higher band
- B. Its valence band is completely full and separated from an empty conduction band by a large gap
- C. Its forbidden energy gap increases rapidly when an electric field is applied
- D. Its electrons remain permanently bound in covalent bonds
Example 3 · difficulty 1/5
At ordinary temperatures, why does an insulator have negligible electrical conductivity?
- A. Its conduction band is completely filled with mobile electrons
- B. Its large forbidden gap prevents appreciable thermal excitation into the conduction band
- C. Its valence and conduction bands strongly overlap
- D. Its atoms supply an equal number of electrons and holes
The evidence-first practice loop
- 1. Verify provenanceOfficial paper and final key before accepting a PYQ label.
- 2. Attempt closed-bookExpose the concept or execution gap before rereading.
- 3. Repair and returnClassify the miss and re-practice after a delay.
Canonical chapter practice
Frequently asked questions
Are these official NEET 2018 Physics Semiconductor Electronics PYQs?
No. The previews are original NeetVellum practice questions. A historical item receives a PYQ label only after its official paper and authoritative final answer key are attached. Use the official archive for the source paper.
How should I use the NEET 2018 paper?
Solve the official paper under its original timing, verify against the final key, classify every miss, and then use the linked current-syllabus practice bank to repair the exposed concept.