Assertion: Magnetic field is useful in producing parallel beam of charged particle.
Reason: Magnetic field inhibits the motion of charged particle moving across it.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
A wire of mass 100 g, length 1 m and current 5 A is balanced in mid air by a magnetic field B, then find the value of B
0.2 T
0.1 T
0.5 T
0.6 T
A toroid with mean radius r0, diameter 2a have turns carrying current I. What is the magnetic field B outside the toroid?
zero
Two wires carrying
Parallel current repel each other.
Antiparallel current attract each other.
Antiparallel current repel each other.
Equal magnitudes of antiparallel current attract each other.
Assertion: A planar circular loop of area A and carrying current I is equivalent to magnetic dipole of dipole moment M = IA.
Reason: At large distances, magnetic field of circular loop and magnetic dipole is same.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
What is the dimensions of a magnetic field B in terms of C ( = coulomb ), M, L, T?
[ M1 L-1 T-2 C ]
[ M1 L0 T-1 C-1 ]
[ M1 L0 T-2 C ]
[ M1 L0 T-1 C ]
Magnetic energy per unit volume is represented by
A.
The emf induced in an inductor
Iε = I2 R + LI
This expression indicates that the rate at which energy is supplied by the battery (Iε ) equals the sum of the rate at which energy energy delivered to the resistor I2R and the rate at which energy is stored in the inductor
Now U is the energy stored in inductor at any time, rate of change of energy is given by
To find the total energy stored in the inductor, dU = LI
U =
= LI dI
U = L I2 ....(i)
where L is constant.
This expression represents the energy stored in the magnetic field of the inductor when current is I.
The energy stored in the electric field of capacitor
U =
Now energy density of magnetic field
L = μ0n2 Al
The magenetic field of a solenoid is given by
B = μ0 nI
Substituting the expression for L and I =
Put above value in eq. (i)
U =
⇒ U =
Because Al is the volume of the solenoid, the energy stored per unit volume in the magnetic field surrounding the inductor is
uB =
⇒ uB =