Electromagnetic Induction & AC · JEE Main previous year questions

2004 3 questions

1. Q1182004 · 24 Apr 2004 · Shift 1

   A current $i$ ampere flows along an infinitely long straight thin walled tube, then the magnetic induction at any point inside the tube is

   1. A.$\frac{{\mu }_0}{4\pi },\frac{2i}{r}$ tesla
   2. B.zero
   3. C.infinite
   4. D.$\frac{2i}{r}$ tesla
   Show answer

   Answer: B

2. Q1242004 · 24 Apr 2004 · Shift 1

   Alternating current can not be measured by $D.C.$ ammeter because

   1. A.Average value of current for complete cycle is zero
   2. B.$A.C.$ Changes direction
   3. C.$A.C.$ can not pass through $D.C.$ Ammeter
   4. D.$D.C.$ Ammeter will get damaged.
   Show answer

   Answer: A

3. Q1282004 · 24 Apr 2004 · Shift 1

   In a $LCR$ circuit capacitance is changed from $C$ to $2C$. For the resonant frequency to remain unchaged, the inductance should be changed from $L$ to

   1. A.$L/2$
   2. B.$2L$
   3. C.$4L$
   4. D.$L/4$
   Show answer

   Answer: A