Correct Answer: E
Explanation:
Current flowing through the conductor is given as
I = neAv
d
--------------- (1)
Putting the values in equation 1 we get
I = 6 × 10
24
1.6 × 10
-19
× 2 × 10
-4
× 10
-3
I = 0.19A
Hence, E is the correct answer option.
Question 13
A long straight conductor carries a current of 2 A. What would be the magnetic field at a distance
of 0.05 m from the axis of the conductor? (Permeability of free space is 4π × 10
-7
WbA
-1
m
-1
)
A.
8 × 10
-6
T
B.
4 × 10
-6
T
C.
2.5 × 10
-6
T
D.
1.5 × 10
-6
T
E.
6 × 10
-6
T
Correct Answer: A
Explanation:
Magnetic field due toalong straight conductor is given as
B = [(μ
0
/4π)(2I/a)] -------------- (1)
Putting the values in equation 1 we get
B = (4π × 10
-7
/ 4π) * (2 * 2 / 0.05)
B = 8 × 10
-6
T
Hence, A is the correct answer option.
Question 14
A small water drop on a surface is viewed through a glass. If the real depth of the water drop is 15
cm, what will be the apparent depth of the water drop? (Refractive index of glass =1.5 and
refractive index of air = 1)
A.
5 cm
B.
7.5 cm
C.
8.4 cm
D.
1.5 cm
E.
10 cm
Correct Answer: E
