Electronics and Communication Engineering - Exam Questions Papers

A sphere with charge Q was placed in, but not touching a larger hollow sphere. If there is any charge initially on the outer sphere; to remove it the outer sphere was earthed momentarily, and then the inner sphere was removed. The charge remaining on the outer sphere was then measured. This charge was found to be __________ to the charge on the inner sphere.

At t = ∞; V_R2 and V_C will be

Two products are sold from a vending machine, which has two push buttons P₁ and P₂. When a button is pressed, the price of the corresponding product is displayed in a 7-segment display. If no buttons are pressed, '0' is displayed, signifying 'Rs' .0'. If only P₁ is pressed, '2' is displayed, signifying 'Rs. 2'.
If only P₂ is pressed, '5' is displayed, signifying 'Rs. 5'.
If both P₁ and P₂ are pressed, 'E' is displayed, signifying 'Error'. The names of the segments in the 7-segment display, and the glow of the display for '0', '2', '5' and 'E', are shown below.

Consider

1. push button pressed/not pressed is equivalent to logic 1/ 0 respectively
2. a segment a to g are considered as functions of P₁ and P₂, then which of the respectively.

If segments a to g are considered as functions of P₁ and P₂, then which of the following is correct?

Laplace transform of {t cos at} is:

The following series RLC circuit with zero initial conditions is excited by a unit impulse function δ(t).

For t > 0, the output voltage V_c (t) is