SATHEE: Electrostatics 1 Question 23

Electrostatics 1 Question 23

24. A pendulum bob of mass $80 mg$ and carrying a charge of $2 \times 10^{- 8} C$ is at rest in a horizontal uniform electric field of $20, 000 V / m$ . Find the tension in the thread of the pendulum and the angle it makes with the vertical.

(Take $g = 9.8 {ms}^{- 2}$ )

(1979)

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Answer:

Correct Answer: 24. $T = 8.79 \times 10^{- 4} N and θ = 27^{\circ}$

Solution:

For equilibrium of bob

$T \cos θ = m g and T \sin θ = q E$

From these two equations we find

$T = \sqrt{(m g)^{2} + (q E)^{2}} and θ = \tan^{- 1} \frac{q E}{m g}$

Substituting the values we have

$\begin{aligned} T & = \sqrt{{(80 \times 10^{- 6} \times 9.8)}^{2} + {(2 \times 10^{- 8} \times 20000)}^{2}} \\ = 8.79 \times 10^{- 4} N \\ θ & = \tan^{- 1} \frac{2 \times 10^{- 8} \times 20000}{80 \times 10^{- 6} \times 9.8} = 27^{\circ} \end{aligned}$

Electrostatics 1 Question 23

24. A pendulum bob of mass $80 mg$ and carrying a charge of $2 \times 10^{- 8} C$ is at rest in a horizontal uniform electric field of $20, 000 V / m$ . Find the tension in the thread of the pendulum and the angle it makes with the vertical.

Answer:

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Electrostatics 1 Question 23

24. A pendulum bob of mass 80mg and carrying a charge of 2×10−8C is at rest in a horizontal uniform electric field of 20,000 V/m. Find the tension in the thread of the pendulum and the angle it makes with the vertical.

Answer:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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24. A pendulum bob of mass $80 mg$ and carrying a charge of $2 \times 10^{- 8} C$ is at rest in a horizontal uniform electric field of $20, 000 V / m$ . Find the tension in the thread of the pendulum and the angle it makes with the vertical.