Download Quiz LEVEL 1 1.The circumstance under which line charge can be

Quiz
LEVEL 1
1.The circumstance under which line charge can be treated as point charge is_
A)E field is being measured at a distance which is much larger than the dimensions of the line
B)E field is measured on the line charge
C)it can never be treated so
D)None of the above
Ans:A
2.In case of dipole the E field at a point is ___
Ans:A
A)inversely proportional to cube of distance B)inversely proportional to square of distance
C)inversely proportional to distance
D)inversely proportional to fourth power of distance
3.E field due to a system of quadrupole is
Ans:D
A)inversely proportional to cube of distance B)inversely proportional to square of distance
C)inversely proportional to distance
D)inversely proportional to fifth power of distance
4.Electric flux lines :
Ans:C
A)emanate from positive charge
B)converge on negative charge
C)both the above
D)none of the above
5. Electric fields due to non uniform distributions cannot be obtained using Gauss’s law
Ans:B
A)True
B)False
C)depends on non uniformity
D)None of the above
6.Which of the following represents a symmetric E field surface for uniformly distributed volume charge:
Ans:A
A)yes
B)no
C)insufficient data
D)none of the above
7. At a distance comparable to the dimensions of the surface charge E field due to it is
Ans:B
A)independent of the distance
C)cannot be determined
B)dependent on distance
D)none of the above
8. Electric Potential inside the perfect spherical conductor is ____________ proportional to the distance from the
centre.
Ans:D
A)Directly
B)Inversely
C)Square of Inverse
D)Constant
9.The unit of polarization is
Ans:B
A)nC/m
B)nC/m2
C)nC/m3
D)nCm2
LEVEL2
1.The intensity of electric field between two parallel charged plates is 5N per coulomb then the fore exerted on a
2.0 coulomb charge placed between the plates is ___
Ans:D
A)0.40
B)2.5
C)7
D)10
2. A long charged cylinder of linear charged density l is surrounded by a hollow co-axial conducting cylinder. What
is the electric field in the space between the two cylinders?Ans:A
A) λ/(2 π ε0 r )
B) λ/(2 π ε0 r2 )
C) λ/( π ε0 r )
C)None
3.Which is not an example of convection current?
Ans D
(a) A moving charged belt
(b) Electronic movement in a vacuum tube
(c) An electron beam in a television tube
(d) Electric current flowing in a copper wire
4. Sea water has εr = 80. Its permittivity is
(a) 81
(b) 79
Ans:D
(c) 5.162 X 10-1 uF/m
(d) 7.074 X 10-10F/m
5. The relaxation time of mica (σ = 10 -15mhos/m εr = 6) is
Ans:C
(a) 5 X 10-10 s
(b) 10-6s
(c) 15 hours
(d) 10 hours
6. The charge 10 -4e-3t ( C is removed from a sphere through a wire. Find the current in the
wire at t= 0 and t = 2.5 s.
A) 4mA
Ans:D
B) 8mA
C)12mA
D)None
7. A coil is made of 150 turns of copper wire wound on a cylindrical core. If the mean radius of the turns is 6.5 mm
and the diameter of the wire is 0.4 mm, calculate the resistance of the coil. Ans:D
A)2.75Ω
B) 2.78Ω
C) 2.73Ω
D)None
LEVEL 3
1.Dielectric breakdown is said to occurred when:
Ans:B
A)Dielectric has broken down due to excessive voltage
B)Dielectric starts conducting
C)Dielectric stops conducting
D)None of these
2.When the ratio of electric field to polarization is divided by ε o. It is called as
Ans:C
A)Relative permittivity
B)Dielectric strength
C)Electric susceptibility
D)None of the above
3. The electric susceptibility Xe ( = εr - 1) of a dielectric measures
A) the sensitivity of the material to an electric field.
B) the sensitivity of the material to a magnetic field.
C)Both
D)None
4.For conductors Ans:A
Ans:A
A) σ>>1, ε r = 1
C) ) σ>>1, ε r ≥ 1
5. For conductors Ans:D
A) σ>>1, ε r = 1
C) ) σ>>1, ε r ≥ 1
B) ) σ<<1, ε r ≥ 1
D) ) σ<<1, ε r = 1
B) ) σ<<1, ε r ≥ 1
D) ) σ<<1, ε r = 1
When a steady potential difference is applied across the ends of a conducting wire
6. Which one is correct
Ans:D
a) All electrons move with a constant velocity.
b) All electrons move with a constant acceleration.
A) a
B)b
C)both
D)none
7. Which one is correct
Ans:A
a) The random electronic motion will, on the average, be equivalent to a constant velocity of each
electron.
b) The random electronic motion will, on the average, be equivalent to a nonzero constant acceleration
of each electron.
A) a
B)b
C)both
D)none