1
GATE EE 2014 Set 2
+2
-0.6
The magnitude of magnetic flux density ($$\overrightarrow B$$) at a point having normal distance d meters from an infinitely extended wire carrying current of I A is $$\frac{\mu_0I}{2\mathrm{πd}}$$ (in SI units). An infinitely extended wire is laid along the x-axis and is carrying current of 4 A in the +ve x direction. Another infinitely extended wire is laid along the y-axis and is carrying 2 A current in the +ve y direction. μ0 is permeability of free space. Assume $$\widehat i,\;\widehat j,\;\widehat k$$ to be unit vectors along x, y and z axes respectively. Assuming right handed coordinate system, magnetic field intensity, $$\overrightarrow H$$ at coordinate (2,1,0) will be
A
$$\frac3{2\mathrm\pi}\widehat k\;$$ Weber/m2
B
$$\frac4{3\mathrm\pi}\widehat i\;A/m$$
C
$$\frac3{2\mathrm\pi}\widehat k\;A/m$$
D
0 A/m
2
GATE EE 2008
+2
-0.6
A coil of 300 turns is wound on a non-magnetic core having a mean circumference of 300 mm and a cross-sectional area of 300 mm2. The inductance the coil corresponding to a magnetizing current of 3 A will be ( Given that $$\mu_0=4\mathrm\pi\times10^{-7}\;\mathrm H/\mathrm m$$)
A
37.6 µH
B
113.04 µH
C
37.68 mH
D
113.04 mH
3
GATE EE 2007
+2
-0.6
An inductor designed with $$400$$ turns coil wound on an iron core of $$16\,\,c{m^2}$$ cross sectional area and with a cut of an air gap length of $$1$$ $$mm$$. The coil is connected to a $$230$$ $$V,$$ $$50$$ $$Hz$$ ac supply. Neglect coil resistance, core loss, iron reluctance and leakage inductance. $$\left( {{\mu _0} = 4\pi \times {{10}^{ - 7}}\,H/m} \right)$$

The current in the inductor is

A
$$18.08$$ $$A$$
B
$$9.04$$ $$A$$
C
$$4.56$$ $$A$$
D
$$2.28$$ $$A$$
4
GATE EE 2007
+2
-0.6
An inductor designed with $$400$$ turns coil wound on an iron core of $$16\,\,c{m^2}$$ cross sectional area and with a cut of an air gap length of $$1$$ $$mm$$. The coil is connected to a $$230$$ $$V,$$ $$50$$ $$Hz$$ ac supply. Neglect coil resistance, core loss, iron reluctance and leakage inductance. $$\left( {{\mu _0} = 4\pi \times {{10}^{ - 7}}\,H/m} \right)$$

The average force on the core to reduce the air gap will be

A
$$832.29$$ $$N$$
B
$$1666.22$$ $$N$$
C
$$3332.47$$ $$N$$
D
$$6664.84$$ $$N$$
EXAM MAP
Medical
NEET