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(A): In equation F=q(E+v xx B) when v = ...

(A): In equation `F=q(E+v xx B)` when v = 0, any force on the charge must arise from the electric field term E alone
(R): To explain, the existence of induced emf or induced current in static conductor kept in time - varying magnetic field, we must assume that a time - varying magnetic field generates an electric field

A

Both A and R are true and R is the correct explanation

B

Both A and R are true but R is not the correct explanation of A

C

A is true but R is false

D

Both A and R are false

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we will analyze both statements (A) and (R) separately and determine their validity. ### Step-by-Step Solution: **Step 1: Analyze Statement (A)** The equation given is \( F = q(E + v \times B) \). Here, \( F \) is the force on a charge \( q \), \( E \) is the electric field, \( v \) is the velocity of the charge, and \( B \) is the magnetic field. When \( v = 0 \), the term \( v \times B \) becomes zero. Therefore, the force \( F \) simplifies to \( F = qE \). This means that if the charge is at rest, any force acting on it must arise solely from the electric field \( E \). Thus, Statement (A) is **true**. **Step 2: Analyze Statement (R)** Statement (R) discusses the existence of induced EMF (Electromotive Force) or induced current in a static conductor placed in a time-varying magnetic field. According to Faraday's law of electromagnetic induction, the induced EMF in a closed loop is given by: \[ \mathcal{E} = -\frac{d\Phi_B}{dt} \] where \( \Phi_B \) is the magnetic flux. A time-varying magnetic field generates an electric field, which can induce an EMF in a conductor. This is also supported by Maxwell's equations, specifically that the curl of the electric field \( \nabla \times E \) is equal to the negative rate of change of the magnetic field \( -\frac{\partial B}{\partial t} \). Therefore, Statement (R) is also **true**. **Step 3: Determine the relationship between (A) and (R)** Both statements (A) and (R) are true, but (R) serves to explain a different concept related to induced EMF in a time-varying magnetic field. Therefore, while both are true, (R) does not directly explain (A). ### Conclusion: - Statement (A) is true. - Statement (R) is true but does not directly explain (A). Thus, the answer to the question is that both statements are true, but (R) does not explain (A).
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AAKASH SERIES-ELECTROMAGNETIC INDUCTION-EXERCISE-IB
  1. A : Total induced emf in a loop is not confined to any particular poin...

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  2. (A): Unlike electrostatic field the lines of induced field from closed...

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  3. A: The mutual Induction between the two coils infinitely apart is zero...

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  4. A: An inductor is called the inertia of an electric circuit. R: An ...

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  5. A: At any instant, if the current through an inductor is zero, then th...

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  6. A: There may be an induced emf in a loop without induced current. R:...

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  7. A: When the magnetic flux through a loop is maximum, induced emf is ma...

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  8. A: When a conducting loop is kept stationary in a non-uniform magnetic...

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  9. A: When an electric motor is started, a variable resistance (that decr...

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  10. A current I is flowing in a straight conductor of length L. The magnet...

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  11. A: Electrical power through transmission lines is transmitted at high ...

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  12. (A): The electric field induced due to changing magnetic field is non-...

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  13. (A): In equation F=q(E+v xx B) when v = 0, any force on the charge mus...

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  14. A: The induced current flows so as to oppose the cause producing it. ...

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  15. (A): Only a change in magnetic flux will maintain an induced current i...

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  16. (A): If changing current is flowing through a machine of iron eddy cur...

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  17. Assertion : The possibility of an electric bulb fusing is higher at t...

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  18. Assertion : An emf vec(E) is induced in a closed loop where magnetic f...

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