In a PN junction diode, the forward bias is increased gradually from 0 Volt to 1 Volt. Which of the following statements is correct?
A. The depletion width increases, and barrier potential increases
B. The depletion width decreases, but the electric field inside the junction increases
C. The depletion width remains unchanged, but current increases
D. The depletion width decreases and barrier potential decreases
B
A
D
C

Two charges 1 C and 2 C are placed at coordinates $(0,3)$ and $(4,3)$ respectively in an XY plane. What is the work done to put a 30 C charge at the origin of the coordinate system?
$1.98 \times 10^9 \mathrm{~J}$
$198 \times 10^9 J$
$19.8 \times 10^9 J$
$3.98 \times 10^9 \mathrm{~J}$

Two long parallel conductors $X$ and $Y$ are placed vertically at a distance $d$ apart. Conductor X carries a current I upwards and conductor Y carries a current 21 downwards. A third long conductor Z is placed parallel to both X and Y and between X and Y . If Z carries a current I upwards and is at a distance $x$ from conductor X , then:
A. All the conductors are in equilibrium and the net force on Z is zero
B. The net force on Z is $\frac{\mu_0 I^2}{2 x \pi}\left[\frac{d+x}{d-x}\right]$ towards X
C. The net force on Z is $\frac{\mu_0 I^2}{2 x \pi}\left[\frac{d+x}{d-x}\right]$ towards Y
D. The net force on Z is $\frac{\mu_0 I^2}{2 x \pi}\left[\frac{d-x}{d+x}\right]$ towards Y
B
D
A
C
A $50 \Omega$ galvanometer is shunted by a resistance of $S \Omega$. If $8 \%$ of total current passes through the galvanometer, the value of $S$ is:
$4 \Omega$
$4.35 \Omega$
$3.9 \Omega$
$3.35 \Omega$
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