Bissoy.com
Doctors Medicines MCQs Q&A

Which of the following correctly represents the sequence of operations of isolator circuit breaker and earthing switch while opening a circuit

Which of the following correctly represents the sequence of operations of isolator circuit breaker and earthing switch while opening a circuit Correct Answer Open circuit breaker – open isolator – close earthing switch

  • Circuit breaker always trips the circuit, but open contacts of breaker cannot be visible physically from outside of the breaker
  • So, it is not recommended to touch any electrical circuit just by switching off the circuit breaker
  • So, for better safety, there must be some arrangement so that one can see the open condition of the section of the circuit before touching it
  • The isolator is a mechanical switch which isolates a part of the circuit from the system as when required
  • Electrical isolators separate a part of the system from rest for safe maintenance works
  • An isolator is installed on both sides of a circuit breaker

 

The sequence of operations of isolator circuit breaker and earthing switch while opening a circuit is

Open circuit breaker – open isolator – close earthing switch

Related Questions

You need to allow one host to be permitted to attach dynamically to each switch interface. Which two commands must you configure on your catalyst switch to meet this policy?
1. Switch (config-if) # ip access-group 10
2. Switch (config-if) # switchport port-security maximum 1
3. Switch (config) # access-list 10 permit ip host 1
4. Switch (config-if) # switchport port-security violation shutdown
5. Switch (config) # mac-address-table secure
A type of circuit breaker which can work up to 15 kV and the rupturing capacity of that circuit breaker is 2500 MVA. Determine the type of circuit breaker mentioned in the context and shown in the given figure.
To pass a test, a candidate needs to answer at least 2 out of 3 questions correctly. A total of 6,30,000 candidates appeared for the test. Question A was correctly answered by 3,30,000 candidates. Question B was answered correctly by 2,50,000 candidates. Question C was answered correctly by 2,60,000 candidates. Both questions A and B were answered correctly by 1,00,000 candidates. Both questions B and C were answered correctly by 90,000 candidates. Both questions A and C were answered correctly by 80,000 candidates. If the number of students answering all questions correctly is the same as the number answering none, how many candidates failed to clear the test?
An isolator has a very large operating bandwidth and independent of any isolator parameter.
For the circuit as shown, consider that switch S1 has been in position B for a very long time and switch S2 has been open all the time. At time t = 0, the switch S1 moves to position A and switch S2 closes instantaneously. What is the value of Vout of t = 0+, assuming initial charge on C = 0?
Which type of earthing is most common and best system of earthing?
Consider four processes P, Q, R, and S scheduled on a CPU as per round-robin algorithm with a time quantum of 4 units. The processes arrive in the order P, Q, R, S, all at time t = 0. There is exactly one context switch from S to Q, exactly one context switch from R to Q, and exactly two context switches from Q to R. There is no context switch from S to P. Switching to a ready process after the termination of another process is also considered a context switch. Which one of the following is NOT possible as CPU burst time (in time units) of these processes?  
Indian Electricity Rules specify the cases where earthing is required. The resistance of the ground to these earthing should be checked
The question given below consists of a statement, followed by three arguments numbered I, II and III. You have to decide which of the arguments is/are ‘strong’ arguments and which is/are ‘weak’ arguments and accordingly choose your answer from the alternatives given below each question. Statement: The imposition of Governor’s rule in Jammu and Kashmir will not affect operations in the state, according to Army Chief General, even as security forces are looking at higher intensity of operations against terrorists, to force them to ‘hibernate’. These operations will be based on greater level of intelligence from the J&K Police, as compared to what was being generated during the suspension of operations for the holy month of Ramzan. A challenge, however, for the security forces still remains the recruitment of local terrorists. Why? Arguments: I. Meanwhile, data shared by security forces reveal that there are about 210 terrorists currently operating in Kashmir, mainly in the South. Out of this, 65 per cent are locals and the remaining are foreign terrorists.  II. In South Kashmir itself, the maximum number of terrorists belong to the HizbulMujahideen, while some are from the Lashkar-e-Toiba and Jaish-e-Mohammed. III. When a local terrorist is killed during an operation, at his funeral more locals are willing to join terrorism. It is a mob mentality.
Which of the following types of connections can use full duplex?
1. Hub to hub
2. Switch to switch
3. Host to host
4. Switch to hub
5. Switch to host