Physics - Electrostatic Potential Capacitance - Quiz-7

A non-conducting ring of radius 0.5 m carries a total charge of 1.11 × 10^–10 C distributed non-uniformly on its circumference producing an electric field $\vec{E}$ everywhere in space. The value of the line integral $\int_{l = \infty}^{l = 0} - \vec{E} . \vec{d l} (l = 0$ being centre of the ring) in volt is

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+ 2
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– 1
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– 2
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Zero

A negatively charged plate has charge density of 2 × 10^–6 C/m². The initial distance of an electron which is moving toward plate but cannot strike the plate, if it is having energy of 200 eV

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(2) 3.51 mm
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(3) 1.77 cm
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(4) 3.51 cm
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(1) 77 mm

Electric potential is given by

$V = 6 x - 8 x y^{2} - 8 y + 6 y z - 4 z^{2}$

Then electric force acting on 2C point charge placed on origin will be

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2N
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6N
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8N
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20N

Consider two points 1 and 2 in a region outside a charged sphere. Two points are not very far away from the sphere. If E and V represent the electric field vector and the electric potential, which of the following is not possible?

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$| {\vec{E}}_{1} | = | {\vec{E}}_{2} |, V_{1} = V_{2}$
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${\vec{E}}_{1} \neq {\vec{E}}_{2}, V_{1} \neq V_{2}$
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${\vec{E}}_{1} \neq {\vec{E}}_{2}, V_{1} = V_{2}$
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$| {\vec{E}}_{1} | = | {\vec{E}}_{2} |, V_{1} \neq V_{2}$

A uniform electric field pointing in positive x-direction exists in a region. Let A be the origin, B be the point on the x-axis at x = +1 cm and C be the point on the y-axis at y = +1 cm. Then the potentials at the points A, B and C satisfy

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V_A < V_B
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V_A > V_B
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V_A < V_C
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V_A > V_C

The electric potential at a point (x, y) in the x – y plane is given by V = –kxy. The field intensity at a distance r from the origin varies as

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r²
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r
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$\frac{1}{r}$
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$\frac{1}{r^{2}}$

Two equal point charges are fixed at x = –a and x = +a on the x-axis. Another point charge Q is placed at the origin. The change in the electrical potential energy of Q, when it is displaced by a small distance x along the x-axis, is approximately proportional to

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x
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x²
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x³
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1/x

A solid conducting sphere having a charge Q is surrounded by an uncharged concentric conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be V. If the shell is now given a charge of –3Q, the new potential difference between the same two surfaces is

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V
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2V
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4V
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–2V

A piece of cloud is having area 25 × 10⁶ m² and electric potential of 10⁵ volts. If the height of cloud is 0.75 km, then energy of electric field between earth and cloud will be

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250 J
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759 J
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1225 J
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1475 J

A parallel plate air capacitor has a capacitance of 100 μF. The plates are at a distance d apart. If a slab of thickness $t (t \leq d)$ and dielectric constant 5 is introduced between the parallel plates, then the capacitance will be

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50 μμF
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100 μμF
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200 μμF
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500 μμF

Capacitance of a capacitor made by a thin metal foil is 2 μF. If the foil is folded with paper of thickness 0.15 mm, dielectric constant of paper is 2.5 and width of paper is 400 mm, then length of foil will be

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0.34 m
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1.33 m
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13.4 m
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33.9 m

A parallel plate capacitor is connected to a battery. The plates are pulled apart with a uniform speed. If x is the separation between the plates, the time rate of change of electrostatic energy of the capacitor is proportional to:

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x^–2
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x
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x^–1
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x²

In the figure below, what is the potential difference between the point A and B and between B and C respectively in steady state

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$V_{A B} = V_{B C} = 100 V$
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$V_{A B} = 75 V, V_{B C} = 25 V$
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$V_{A B} = 25 V, V_{B C} = 75 V$
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$V_{A B} = V_{B C} = 50 V$

Figure given below shows two identical parallel plate capacitors connected to a battery with switch S closed. The switch is now opened and the free space between the plate of capacitors is filled with a dielectric of dielectric constant 3. What will be the ratio of total electrostatic energy stored in both capacitors before and after the introduction of the dielectric

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3 : 1
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5 : 1
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3 : 5
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5 : 3

A parallel plate capacitor of capacitance C is connected to a battery and is charged to a potential difference V. Another capacitor of capacitance 2C is connected to another battery and is charged to potential difference 2V. The charging batteries are now disconnected and the capacitors are connected in parallel to each other in such a way that the positive terminal of one is connected to the negative terminal of the other. The final energy of the configuration is?

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Zero
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$\frac{25 C V^{2}}{6}$
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$\frac{3 C V^{2}}{2}$
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$\frac{9 C V^{2}}{2}$

Condenser A has a capacity of 15 μF when it is filled with a medium of dielectric constant 15. Another condenser B has a capacity of 1 μF with air between the plates. Both are charged separately by a battery of 100 V. After charging, both are connected in parallel without the battery and the dielectric medium being removed. The common potential now is

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400 V
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800 V
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1200 V
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1600 V

Four metallic plates each with a surface area of one side A are placed at a distance d from each other. The plates are connected as shown in the circuit diagram. Then the capacitance of the system between a and b is

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$\frac{3 ε_{0} A}{d}$
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$\frac{2 ε_{0} A}{d}$
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$\frac{2 ε_{0} A}{3 d}$
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$\frac{3 ε_{0} A}{2 d}$

In the given circuit if point C is connected to the earth and a potential of +2000 V is given to the point A, the potential at B is

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1500 V
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1000 V
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500 V
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400 V

A finite ladder is constructed by connecting several sections of 2 μF, 4 μF capacitor combinations as shown in the figure. It is terminated by a capacitor of capacitance C. What value should be chosen for C such that the equivalent capacitance of the ladder between the points A and B becomes independent of the number of sections in between

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4 μF
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2 μF
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18 μF
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6 μF

In an isolated parallel plate capacitor of capacitance C, the four surface have charges Q₁, Q₂, Q₃ and Q₄ as shown. The potential difference between the plates is

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$\frac{Q_{1} + Q_{2} + Q_{3} + Q_{4}}{2 C}$
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$\frac{Q_{2} + Q_{3}}{2 C}$
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$\frac{Q_{2} - Q_{3}}{2 C}$
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$\frac{Q_{1} + Q_{4}}{2 C}$

For the circuit shown, which of the following statements is true

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With S₁ closed, V₁ = 15 V, V₂ = 20 V
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With S₃ closed V₁ = V₂ = 25 V
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With S₁ and S₂ closed V₁ = V₂ = 0
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With S₁and S₃closed, V₁ = 30 V, V₂ = 20 V

Consider the situation shown in the figure. The capacitor A has a charge q on it whereas B is uncharged. The charge appearing on the capacitor B a long time after the switch is closed is

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Zero
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q/2
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q
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2q

A capacitor of capacitance C₁ = 1 μF can withstand maximum voltage V₁ = 6kV (kilo-volt) and another capacitor of capacitance C₂ = 3 μF can withstand maximum voltage V₂ = 4 kV. When the two capacitors are connected in series, the combined system can withstand a maximum voltage of

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4 kV
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6 kV
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8 kV
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10 kV

The plates of a capacitor are charged to a potential difference of 320 volts and are then connected across a resistor. The potential difference across the capacitor decays exponentially with time. After 1 second the potential difference between the plates of the capacitor is 240 volts, then after 2 and 3 seconds the potential difference between the plates will be

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200 and 180 V
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180 and 135 V
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160 and 80 V
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140 and 20 V

The plates of a parallel plate condenser are pulled apart with a velocity v. If at any instant their mutual distance of separation is d, then the magnitude of the time rate of change of capacity depends on d as follows

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1/d
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1/d²
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d²
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d

A fully charged capacitor has a capacitance ‘C’. It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity ‘s’ and mass ‘m’. If the temperature of the block is raised by ‘ΔT’, the potential difference ‘V’ across the capacitance is

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$\frac{m s Δ T}{C}$
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$\sqrt{\frac{2 m s Δ T}{C}}$
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$\sqrt{\frac{2 m C Δ T}{s}}$
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$\frac{m C Δ T}{s}$

A network of four capacitors of capacity equal to $C_{1} = C, C_{2} = 2 C, C_{3} = 3 C$ and C₄ = 4 C are connected in a battery as shown in the figure. The ratio of the charges on C₂ and C₄ is

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$\frac{22}{3}$
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$\frac{3}{22}$
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$\frac{7}{4}$
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$\frac{4}{7}$

The variation of potential with distance R from a fixed point is as shown below. The electric field at R = 5 m is

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2.5 volt/m
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–2.5 volt/m
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2/5 volt/m
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–2/5 volt/m

The figure gives the electric potential V as a function of distance through five regions on x-axis. Which of the following is true for the electric field E in these regions

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$E_{1} > E_{2} > E_{3} > E_{4} > E_{5}$
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$E_{1} = E_{3} = E_{5}$ and $E_{2} < E_{4}$
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$E_{2} = E_{4} = E_{5}$ and $E_{1} < E_{3}$
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$E_{1} < E_{2} < E_{3} < E_{4} < E_{5}$

In a hollow spherical shell potential (V) changes with respect to distance (r) from centre

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Practice Physics Quiz Questions and Answers

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Practice Physics Quiz Questions and Answers

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