NAS - MID-I PRACTICE QUESTIONS
MULTIPLE CHOICE QUESTION AND ANSWERS
======================================================================1. A graph is said to be a directed graph if ________ of the graph has direction.
Answer is D)
Explanation:If every branch of the graph has direction, then the graph is said to be a directed graph. If the graph does not have any direction then that graph is called undirected graph.
2. If the current in one coil becomes steady, the current in neighboring coil is?
Answer is A)
A current is induced when there is changing magnetic flux. Hence the induced current in neighbouring coil is zero when the current is steady.
3. If no two branches of the graph cross each other, then the graph is called?
Answer is C)
Explanation: If a graph can be drawn on a plane surface such that no two branches of the graph cross each other, then the graph is called planar graph.
4. If the flux linkage in coil 1 is 3Wb and it has 500 turns and the current in coil 2 is 2A, calculate the mutual inductance..
Answer is A)
Explanation: We know that mutual inductance is the product of the number of turns in one coil and the flux linkages of that coil, divided by the current in the other coil. M=3*500/2=750H..5.The flux linkage in coil 1 is 3Wb and it has x turns and the current in coil 2 is 2A, calculate the value of x if the mutual inductance is 750H.
Answer is C)
Explanation: We know that mutual inductance is the product of the number of turns in one coil and the flux linkages of that coil, divided by the current in the other coil. N=750*2/3 = 500 turns..6. What is the direction of the cut-set?
Answer is A)
Explanation: A cut-set is a minimal set of branches of a connected graph such that the removal of these branches causes the graph to be cut into exactly two parts. The direction of the cut-set is same as the direction of the branch current.7. Practical application of mutual inductance is ____________
Answer is C)
Explanation: A transformer is a device made of two or more inductors, one of which is powered by AC, inducing an AC voltage across the second inductor.8 Tie-set is also called?
Answer is B)
Explanation: The fundamental loop formed by one link has a unique path in the tree joining the two nodes of the link. This loop is also called f-loop.9. What is the coupling coefficient when there is ideal coupling?
Answer is B)
Explanation: When all the flux of coil 1 links with coil 2 it is known as an ideal coupling where the coupling coefficient is 1.10. Number of twigs in a tree are? (where, n-number of nodes)
Answer is C)
Explanation: Twig is a branch in a tree. Number of twigs in a tree are n-1. If there are 4 nodes in a tree then number of possible twigs are 3.11. The number of branches incident at the node of a graph is called?
Answer is A)
Explanation: Nodes can be incident to one or more elements. The number of branches incident at the node of a graph is called degree of the node.12. Can the coupling coefficient practically ever be equal to 1?
Answer is B)
Explanation: All the flux of coil 1 can never link with coil 2. Loss occurs practically due to which coupling coefficient cannot be equal to 1.13. A portion of a graph is called _______.
Answer is C)
Explanation: A portion of the graph is called tree.14. A RC integrator is also known as ____________________.
Answer is D)
Explanation:The RC type Integrator is a type of Low Pass Filter.15.A RC Differentiator is also known as ____________________.
Answer is D)
Explanation:The RC type Integrator is a type of Low Pass Filter.16. Capacitor act as a _____________circuit at t =.∞ (Final Condition for inductor)
Answer is A)
At its final condition, a capacitor acts as an open circuit. This means that there is a break in the circuit.17. Inductor act as a _____________circuit at t =.∞ (Final Condition for inductor)
Answer is B)
Explanation:At \(t=\infty \), an inductor acts as a short circuit. This is because the inductor has no voltage drop across it and no longer generates current.18. At DC, capacitor acts as _________
Answer is A)
Explanation: Capacitive Reactance XC = 1/(2πfC) For DC, f=0 so, XC becomes infinite. Hence for dc, the capacitor acts as an open circuit.19. In an RL series circuit, when the switch is closed and the circuit is complete, what is the response?
Answer is B)
Explanation: In an RL series circuit, the response decays with time because according to the equation, there is an exponential decrease in the response.20. There are 6 branches and 2 essential nodes then how many equations are required to describe a circuit in the mesh-current method.
Answer is C)
Explanation: In Mesh-Current method, b-(n-1) equations are required to describe the circuit. b= the number of branches and n= the number of essential nodes. So, 6-(2-1) =5.