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PHXII08:ELECTROMAGNETIC WAVES

368910 An $a c$ source is connected to a capacitor $C$ .
Due to decrease in its operating frequency:

1 displacement current increases

2 displacement current decreases

3 capacitive reactance remains constant

4 capacitive reactance decreases.

Explanation:

$i_{C} = i_{D} = \frac{V_{0}}{X_{C}} \sin ω t$
$i_{C} = i_{D} = (V_{0} ω C) \sin ω t$
$\Rightarrow i_{C} = i_{D} = V_{0} (2 π f) C \sin ω t$
$\Rightarrow i_{C} = i_{D} = V (2 π f) C \sin ω t$ .
$\Rightarrow$ If $f$ decreases, $i_{C}$ also decreases.
Correct option is (2).

NEET - 2023

PHXII08:ELECTROMAGNETIC WAVES

368911 A parallel plate capacitor of plate separation $2 m m$ is connected in an electric circuit having source voltage $400 V$ . If the plate area is $60 c m^{2}$ , then the value of displacement current for $10^{- 6} \sec$ will be $[I n 10^{- 6} s$ voltage across capacitor becomes 400 volt]

1

1.062 \times 10^{- 4} a m p

2

1.062 \times 10^{- 2} a m p

3

1.062 a m p

4

1.062 \times 10^{- 3} a m p

Explanation:

$I_{d} = ε_{0} \frac{d ϕ_{E}}{d t} = ε_{0} \frac{E A}{t} = \frac{ε_{0} A}{t} \frac{V}{d}$
$I_{d} = \frac{8.85 \times 10^{- 12} \times 400 \times 60 \times 10^{- 4}}{2 \times 10^{- 3} \times 10^{- 6}}$
$= 1.062 \times 10^{- 2} a m p$

PHXII08:ELECTROMAGNETIC WAVES

368912 Which of the following statements is/are correct?
(I) Displacement current happens because of changing electric field.
(II) Displacement current happens because of motion of charged particles.

1 both (I) and (II) are correct

2 only (I) is correct

3 only (II) is correct

4 both (I) and (II) are incorrect

PHXII08:ELECTROMAGNETIC WAVES

368913 The Maxwell's four equations are written as
(i) $\oint_{s} \bar{E} \cdot d \bar{s} = \frac{q}{ε_{o}}$
(ii) $\oint_{S} B . d s = 0$
(iii) $\oint_{S} E \cdot d l = \frac{d}{d t} \int_{S} B \cdot d s$
(iv) $\int \bar{B} \cdot d \bar{l} = μ_{0} I + μ_{0} ε_{0} \frac{d}{d t} \int \bar{E} \cdot d \bar{s}$
The correct equations are

1 (i), (ii)

2 (i) and (iii) only

3 (i), (ii), (iii)

4 (i) and (iv) only

PHXII08:ELECTROMAGNETIC WAVES

368910 An $a c$ source is connected to a capacitor $C$ .
Due to decrease in its operating frequency:

1 displacement current increases

2 displacement current decreases

3 capacitive reactance remains constant

4 capacitive reactance decreases.

Explanation:

$i_{C} = i_{D} = \frac{V_{0}}{X_{C}} \sin ω t$
$i_{C} = i_{D} = (V_{0} ω C) \sin ω t$
$\Rightarrow i_{C} = i_{D} = V_{0} (2 π f) C \sin ω t$
$\Rightarrow i_{C} = i_{D} = V (2 π f) C \sin ω t$ .
$\Rightarrow$ If $f$ decreases, $i_{C}$ also decreases.
Correct option is (2).

NEET - 2023

PHXII08:ELECTROMAGNETIC WAVES

368911 A parallel plate capacitor of plate separation $2 m m$ is connected in an electric circuit having source voltage $400 V$ . If the plate area is $60 c m^{2}$ , then the value of displacement current for $10^{- 6} \sec$ will be $[I n 10^{- 6} s$ voltage across capacitor becomes 400 volt]

1

1.062 \times 10^{- 4} a m p

2

1.062 \times 10^{- 2} a m p

3

1.062 a m p

4

1.062 \times 10^{- 3} a m p

Explanation:

$I_{d} = ε_{0} \frac{d ϕ_{E}}{d t} = ε_{0} \frac{E A}{t} = \frac{ε_{0} A}{t} \frac{V}{d}$
$I_{d} = \frac{8.85 \times 10^{- 12} \times 400 \times 60 \times 10^{- 4}}{2 \times 10^{- 3} \times 10^{- 6}}$
$= 1.062 \times 10^{- 2} a m p$

PHXII08:ELECTROMAGNETIC WAVES

368912 Which of the following statements is/are correct?
(I) Displacement current happens because of changing electric field.
(II) Displacement current happens because of motion of charged particles.

1 both (I) and (II) are correct

2 only (I) is correct

3 only (II) is correct

4 both (I) and (II) are incorrect

PHXII08:ELECTROMAGNETIC WAVES

368913 The Maxwell's four equations are written as
(i) $\oint_{s} \bar{E} \cdot d \bar{s} = \frac{q}{ε_{o}}$
(ii) $\oint_{S} B . d s = 0$
(iii) $\oint_{S} E \cdot d l = \frac{d}{d t} \int_{S} B \cdot d s$
(iv) $\int \bar{B} \cdot d \bar{l} = μ_{0} I + μ_{0} ε_{0} \frac{d}{d t} \int \bar{E} \cdot d \bar{s}$
The correct equations are

1 (i), (ii)

2 (i) and (iii) only

3 (i), (ii), (iii)

4 (i) and (iv) only

PHXII08:ELECTROMAGNETIC WAVES

368910 An $a c$ source is connected to a capacitor $C$ .
Due to decrease in its operating frequency:

1 displacement current increases

2 displacement current decreases

3 capacitive reactance remains constant

4 capacitive reactance decreases.

Explanation:

$i_{C} = i_{D} = \frac{V_{0}}{X_{C}} \sin ω t$
$i_{C} = i_{D} = (V_{0} ω C) \sin ω t$
$\Rightarrow i_{C} = i_{D} = V_{0} (2 π f) C \sin ω t$
$\Rightarrow i_{C} = i_{D} = V (2 π f) C \sin ω t$ .
$\Rightarrow$ If $f$ decreases, $i_{C}$ also decreases.
Correct option is (2).

NEET - 2023

PHXII08:ELECTROMAGNETIC WAVES

368911 A parallel plate capacitor of plate separation $2 m m$ is connected in an electric circuit having source voltage $400 V$ . If the plate area is $60 c m^{2}$ , then the value of displacement current for $10^{- 6} \sec$ will be $[I n 10^{- 6} s$ voltage across capacitor becomes 400 volt]

1

1.062 \times 10^{- 4} a m p

2

1.062 \times 10^{- 2} a m p

3

1.062 a m p

4

1.062 \times 10^{- 3} a m p

Explanation:

$I_{d} = ε_{0} \frac{d ϕ_{E}}{d t} = ε_{0} \frac{E A}{t} = \frac{ε_{0} A}{t} \frac{V}{d}$
$I_{d} = \frac{8.85 \times 10^{- 12} \times 400 \times 60 \times 10^{- 4}}{2 \times 10^{- 3} \times 10^{- 6}}$
$= 1.062 \times 10^{- 2} a m p$

PHXII08:ELECTROMAGNETIC WAVES

368912 Which of the following statements is/are correct?
(I) Displacement current happens because of changing electric field.
(II) Displacement current happens because of motion of charged particles.

1 both (I) and (II) are correct

2 only (I) is correct

3 only (II) is correct

4 both (I) and (II) are incorrect

PHXII08:ELECTROMAGNETIC WAVES

368913 The Maxwell's four equations are written as
(i) $\oint_{s} \bar{E} \cdot d \bar{s} = \frac{q}{ε_{o}}$
(ii) $\oint_{S} B . d s = 0$
(iii) $\oint_{S} E \cdot d l = \frac{d}{d t} \int_{S} B \cdot d s$
(iv) $\int \bar{B} \cdot d \bar{l} = μ_{0} I + μ_{0} ε_{0} \frac{d}{d t} \int \bar{E} \cdot d \bar{s}$
The correct equations are

1 (i), (ii)

2 (i) and (iii) only

3 (i), (ii), (iii)

4 (i) and (iv) only

PHXII08:ELECTROMAGNETIC WAVES

368910 An $a c$ source is connected to a capacitor $C$ .
Due to decrease in its operating frequency:

1 displacement current increases

2 displacement current decreases

3 capacitive reactance remains constant

4 capacitive reactance decreases.

Explanation:

$i_{C} = i_{D} = \frac{V_{0}}{X_{C}} \sin ω t$
$i_{C} = i_{D} = (V_{0} ω C) \sin ω t$
$\Rightarrow i_{C} = i_{D} = V_{0} (2 π f) C \sin ω t$
$\Rightarrow i_{C} = i_{D} = V (2 π f) C \sin ω t$ .
$\Rightarrow$ If $f$ decreases, $i_{C}$ also decreases.
Correct option is (2).

NEET - 2023

PHXII08:ELECTROMAGNETIC WAVES

368911 A parallel plate capacitor of plate separation $2 m m$ is connected in an electric circuit having source voltage $400 V$ . If the plate area is $60 c m^{2}$ , then the value of displacement current for $10^{- 6} \sec$ will be $[I n 10^{- 6} s$ voltage across capacitor becomes 400 volt]

1

1.062 \times 10^{- 4} a m p

2

1.062 \times 10^{- 2} a m p

3

1.062 a m p

4

1.062 \times 10^{- 3} a m p

Explanation:

$I_{d} = ε_{0} \frac{d ϕ_{E}}{d t} = ε_{0} \frac{E A}{t} = \frac{ε_{0} A}{t} \frac{V}{d}$
$I_{d} = \frac{8.85 \times 10^{- 12} \times 400 \times 60 \times 10^{- 4}}{2 \times 10^{- 3} \times 10^{- 6}}$
$= 1.062 \times 10^{- 2} a m p$

PHXII08:ELECTROMAGNETIC WAVES

368912 Which of the following statements is/are correct?
(I) Displacement current happens because of changing electric field.
(II) Displacement current happens because of motion of charged particles.

1 both (I) and (II) are correct

2 only (I) is correct

3 only (II) is correct

4 both (I) and (II) are incorrect

PHXII08:ELECTROMAGNETIC WAVES

368913 The Maxwell's four equations are written as
(i) $\oint_{s} \bar{E} \cdot d \bar{s} = \frac{q}{ε_{o}}$
(ii) $\oint_{S} B . d s = 0$
(iii) $\oint_{S} E \cdot d l = \frac{d}{d t} \int_{S} B \cdot d s$
(iv) $\int \bar{B} \cdot d \bar{l} = μ_{0} I + μ_{0} ε_{0} \frac{d}{d t} \int \bar{E} \cdot d \bar{s}$
The correct equations are

1 (i), (ii)

2 (i) and (iii) only

3 (i), (ii), (iii)

4 (i) and (iv) only