List of practice Questions

Two statements are given one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the codes (A), (B), (C) and (D) as given below.
Assertion (A): A hole is an apparent free particle with effective positive electronic charge.
Reason (R): A hole is not necessarily a vacancy left behind by an electron in the valence band.
Solve the following pair of equations algebraically:
\[ 101x + 102y = 304 \quad \text{(i)}\\ 102x + 101y = 305 \quad \text{(ii)} \]
A sample of a liquid is kept at 1 atm. It is compressed to 5 atm which leads to change of volume of 0.8 cm$^3$. If the bulk modulus of the liquid is 2 GPa, the initial volume of the liquid was ______ litre. (Take 1 atm = $10^5$ Pa)
A current flows through a cylindrical conductor of radius \( R \). The current density at a point in the conductor is \( j = \alpha r \) (along its axis), where \( \alpha \) is a constant and \( r \) is the distance from the axis of the conductor. The current flowing through the portion of the conductor from \( r = 0 \) to \( r = \frac{R}{2} \) is proportional to:
Assertion (A): EM waves do not require a medium for their propagation.
Reason (R): EM waves are transverse waves.
Write vector form of Biot–Savart law.

An ideal transformer is designed to convert 50 V into 250 V. It draws 200 W power from an AC source whose instantaneous voltage is given by \( v_i = 20 \sin(100\pi t) \, \text{V} \).

Find:

  • 1. RMS value of input current.
  • 2. Expression for instantaneous output voltage.
  • 3. Expression for instantaneous output current.
Two coils ‘1’ and ‘2’ are placed close to each other as shown in the figure. Find the direction of induced current in coil ‘1’ in each of the following situations, justifying your answers:
Two coils ‘1’ and ‘2’ are placed

(a) Coil ‘2’ is moving towards coil ‘1’.
(b) Coil ‘2’ is moving away from coil ‘1’.
(c) The resistance connected with coil ‘2’ is increased keeping both the coils stationary.
Two small solid metal balls A and B of radii \(R\) and \(2R\) having charge densities 2 and 3 respectively are kept far apart. Find the charge densities on A and B after they are connected by a conducting wire.
A cell of emf \( E \) and internal resistance \( r \) is connected to an external variable resistance \( R \). Plot a graph showing the variation of terminal voltage \( V \) of the cell as a function of current \( I \), supplied by the cell. Explain how the emf of the cell and its internal resistance can be found from it.
Find the nature of roots of the equation \(3x^2 - 4\sqrt{3}x + 4 = 0\).
Current I (= 1 A) is passing through a copper rod (n = \(8.5 \times 10^{28} \, \text{m}^{-3}\)) of varying cross-sections as shown in the figure. The areas of cross-section at points A and B along its length are \(1.0 \times 10^{-7} \, \text{m}^2\) and \(2.0 \times 10^{-7} \, \text{m}^2\) respectively. Calculate:
Current I (= 1 A) is passing through a copper rod
(I) the ratio of electric fields at points A and B.
(II) the drift velocity of free electrons at point B.
Identify the correct python statement to open a text file \texttt{"data.txt"} in both read and write mode.
Identify the type of expression where operators are placed before the corresponding operands:
Evaluate the postfix expression: \[ 24 \; 5 \; 7 \; \; 5 \; / \; + \]
STACK follows __________ principle, where insertion and deletion is from __________ end/ends only.
Given a scenario: Suppose there is a web-server hosting a website to declare results. This server can handle a maximum of 100 concurrent requests to view results. So, as to serve thousands of user requests, a __________ would be the most appropriate data structure to use.
To perform enqueue and dequeue efficiently on a queue, which of the following operations are required?
A) isEmpty
B) peek
C) isFull
D) update
Identify the correct place where we have to use repeaters.
In MAC address, Organisational Unique Identifier (OUI) consists of __________.

Given a list numList of n elements and key value K, arrange the following steps for finding the position of the key K in the numList using the binary search algorithm i.e. BinarySearch(numList, key).

 

  1. (A) Calculate mid = (first + last) // 2
  2. (B) SET first = 0, last = n - 1
  3. (C) PRINT "Search unsuccessful"
  4. (D) WHILE first <= last REPEAT
    • IF numList[mid] = key, 
      PRINT "Element found at position", mid+1
      STOP
    • ELSE
      • IF numList[mid] > key, THEN last = mid - 1
      • ELSE first = mid + 1
In binary search, after every pass of the algorithm, the search area:
For binary search, the list is in ascending order and the key is present in the list. If the middle element is less than the key, it means:
Arrange the following in order related to bubble sort for a list of elements: Initial list: \[4, -9, 12, 30, 2, 6\] (A) \[4, -9, 12, 30, 2, 6\]
(B) \[-9, 4, 12, 30, 2, 6\]
(C) \[-9, 4, 12, 2, 30, 6\]
(D) \[-9, 4, 12, 2, 6, 30\]
The amount of time an algorithm takes to process a given data can be called its: