Maximum torque acting on an electric dipole of moment 3 × 10 - 29 Cm in a uniform electric field E is 6 × 10 - 25 Nm . Find E .

When an electric dipole moment is kept in an electric field, force acts on both charges in a dipole. The force acting on the charges acts as a couple and the dipole experiences a torque. The torque is maximum when it makes 90 o with the electric field, which is the most unstable position. According to expression of torque experienced by dipole in electric field= 𝜏 = PE sinθ 𝜏 max = pE , θ = 90 ° ⇒ E = 𝜏 max P = 6 2 × 10 - 25 3 × 10 - 29 ∴ E = 2 × 10 4 NC -1

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NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 1 - Electric Charges and Fields>QUESTIONS>Q 38

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What will be the net electric force acting on an electric dipole placed in a uniform electric field?

Important Questions on Electric Charges and Fields

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NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 1 - Electric Charges and Fields>QUESTIONS>Q 39

Maximum torque acting on an electric dipole of moment

3 \times 10^{- 29} Cm

in a uniform electric field

E

is

6 \times 10^{- 25} Nm

. Find

E

.

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NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 1 - Electric Charges and Fields>QUESTIONS>Q 1

The tyres of aircrafts are not made of ordinary rubber (which is an insulator) but of a special rubber which is slightly conducting. Why?

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NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 1 - Electric Charges and Fields>QUESTIONS>Q 2

Vehicles carrying inflammable material usually have metallic chains touching the ground during motion. Why?

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NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 1 - Electric Charges and Fields>QUESTIONS>Q 3

How many electrons must be removed from a piece of metal to give it

+ 1.0 \times 10^{- 7} C

of charge?

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NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 1 - Electric Charges and Fields>QUESTIONS>Q 4

An isolated metallic conductor is positively-charged. Will its mass increase, decrease or remain the same? What if the conductor be negatively-charged?

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NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 1 - Electric Charges and Fields>QUESTIONS>Q 5

A charge

q

is divided into two parts such that they repel each other with a maximum force when placed at a certain distance apart. How has the charge been divided?

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NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 1 - Electric Charges and Fields>QUESTIONS>Q 6

Is there any lower limit of electric force between two charges