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                                              Unit-I: Electrostatics-I

Section-I:               Multiple choice questions

 1. The divergence theorem [   ]

a) Relates a line integral to a surface integral. b) holds for specific vector fields only.

c) Works for open surfaces. d) Relates a surface integral to a volume integral.

2.  which one of the following is not Maxwell equation?  [  ]

3. Which of the following is zero?   [  ]

 a)grad div b)curl grad c)div grad d)curl curl

4.  The field intensity due to a point charge Q at a distance, R, is E1. If charge is increased to ‘4Q’ and distance is increased to ‘2R’, the field intensity E2 becomes [ ]

(a)   E2 = E1 (b) E2 = 4E1 (c) E2 = 2E1 (d) E2 = E1/2

5.  Electrostatic field being conservative doe s not mean [      ] 

(a) Its circulation is identically zero (b) the work done in side a closed path inside the field is zero

(c) The potential difference between any two point s is zero (d) it is the gradient of a scalar potential

6.  A charge Q is uniformly distributed in a sphere of radius a1 the charge density, if the same charge Q is made to occupy a sphere of radius a2=a1/4 is [      ] 

(a) 16 times more (b) 4 times more (c) 64 times more (d) 2 times more

7. The Electric Field inside a uniformly charged spherical shell is [ ]

( a ) unity ( b ) zero ( c ) infinite ( d ) undefined

8.  Gaussian surface encloses a collection of negative charges, then for such a surface, the normal component of Electric Flux Density will become [ ]

( a ) zero ( b ) point outwards ( c ) point inwards ( d ) infinity

9.

 

Section-II:   Fill in the blanks

10. If the electric flux density, D and electric field intensity, E are not in the same direction, the material is called as ____________

11. Value of permeability of free space is ___________

12. According to _________,electrical flux due to any closed surface is equal to the charge enclosed by the surface.

13. Point charges 30 nC , - 20nC and 10 nC are located at (-1,0, 2) , (0,0, 0) and (1,5,-1) respectively. The total flux leaving a cube of side 6m centered at the origin is ________.

14. The Electric Flux Density is __________ to the electric flux lines

15. The curl of a gradient is _________

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SECTION-I:

CHOOSE THE CORRECT ANSWERS

1. The lower cutoff frequency of a low pass RC circuit is [ ]

( a ) 0 ( b ) 2πRC ( c ) 1/2πRC ( d ) infinity

2.The transmission error at the end of the ramp input is defined as [ ]

( a ) (output-input)/output ( b ) (output-input)/input ( c )(input-output)/output 

( d ) (input-output)/output  

3. For double differentiation, two high –pass networks are connected in cascade with time constants of    [   ]

( a ) first one is small and second is large ( b ) first one is large and next is small

( c ) both are small ( d ) both are large

4. What is the response of step input to a high pass RC circuit [ ]

a) V e^-t/RC b) V (1- e^t/RC) c) V e^t/RC d) V(1- e^-t/RC )

5. When RC high pass circuit act as a differentiator? [ ]

a) RC<<T b) RC>>T c)RC=T d)RC=0

6. What is the name of the circuit which converts square wave in to spikes [ ]

a) Low pass RC b) Bi stable multi c) High pass RC d) Monoshot

7.The waveform which preserves its form when transmitted through a linear network is a

___________. [ ]

(a) Sine wave (b) Step signal (c) impulse signal (d) ramp signal

8. An RC high pass circuit has R= 1kΩ and C=0.5 μF. Its lower cutoff frequency is [ ]

(a) zero (b) 318.3 Hz (c) 1kHz (d) infinity

9. For a integrator, if input is square wave then the output waveform is _____ [ ]

(a) Impulse (b) Sawtooth wave (c) Triangular wave (d) Both a and c

10. Gain of integrator ________ with frequency. [ ]

(a) decreases (b) increases (c) both a and b (d) no change

11. A ringing circuit has a quality factor Q=24. This circuit will ring for how many number of cycles? [ ] 

(a) 24 (b) 12 (c) 8 (d) 6

12. The rise time of the output of a low pass RC circuit is given by [ ]

(a) 2.2 RC (b) 0.35/f_H (c) 2.2τ (d) all the above 

Section-II

Fill in the blanks

13. High-pass circuit is treated as a differentiator, if the phase shift between the input and output is at least ___________

14. The condition for perfect compensation of an attenuator is ________

15. For DC input signal capacitor C acts as a ___________

16. The average value of the output value of an RC high pass circuit is _________

17. In RC integrator circuit the output is taken across --------

18. The current flowing through the capacitor when the voltage across the capacitor is V __________

19. The output voltage Vo of RC differentiator for input Vi is ____________

20. _____________ is the condition for an RC high pass circuit to acts as a differentiator.

21. Time constant of RL circuit is ____________.

22. Rise time of a Low pass filter is ________________________.

23. The process of converting pulses into spikes is called _____________.

24.. Write the relationship between time constant and tilt?

                                                                                                                    

                                                                               

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