1
GATE ECE 2006
MCQ (Single Correct Answer)
+2
-0.6
A medium of relative permittivityb $${\varepsilon _r} = 2$$ forms an interface with free-space. A point source of electromagnetic energy is located in the medium at a depth of $$1$$ meter from the interface. Due to the total internal reflection, the transmitted beam has a circular cross-section over the interface. The area of the beam cross-section at the interface is given by
A
$$2\pi \,{m^2}$$
B
$${\pi ^2}\,{m^2}$$
C
$$\pi /2\,{m^2}$$
D
$$\pi \,{m^2}$$
2
GATE ECE 2006
MCQ (Single Correct Answer)
+1
-0.3
The electric field of an electromagnetic wave propagating in the positive z-direction is given by $$$E = {\widehat a_x}\sin \left( {\omega t - \beta z} \right) + {\widehat a_y}\sin \left( {\omega t - \beta z + \pi /2} \right)$$$

The wave is

A
linearly polarized in the z-direction
B
elliptically polarized
C
left-hand circularly polarized
D
right-hand circularly polarized
3
GATE ECE 2006
MCQ (Single Correct Answer)
+1
-0.3
$$\int\int\left(\nabla\times\mathrm P\right)\;\cdot\mathrm{ds}$$ , where is a vector, is equal to
A
$$\mathrm P\times\nabla\times\mathrm P\;-\;\nabla^2\;\mathrm P$$
B
$$\nabla^2\;\mathrm P\;+\;\nabla\left(\nabla\cdot\mathrm P\right)$$
C
$$\nabla^2\;\mathrm P\;+\;\nabla\times\mathrm P$$
D
$$\nabla\left(\nabla\cdot\mathrm P\right)-\nabla^2\;\mathrm P\;$$
4
GATE ECE 2006
MCQ (Single Correct Answer)
+2
-0.6
An n-channel depletion MOSFET has following two points on its ID − VGS curve:
(i) VGS = 0 at ID = 12 mA and
(ii) VGS = - 6 Volts at ID = 0
Which of the following Q-points will give the highest trans-conductance gain for small signals?
A
VGS = -6 Volts
B
VGS = -3 Volts
C
VGS = 0 Volts
D
VGS = 3 Volts
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