The air envelope surrounding the earth is called ___

A 16 A, Type B Miniature Circuit Breaker (MCB) will disconnect a fault in 0.1s when the fault current is

Class B trip curve:
The MCB with class B trip characteristics trips instantaneously when the current flowing through it reaches between 3 to 5 times rated current. These MCBs are suitable for cable protection.
Hence, For 16 A current Type B MCB disconnect fault at 3*16 = 48 A to 5*16 = 80 A.

The Prime Minister Rozgar Yojana (PMRY) was launched in which year?

Simultaneous tripping of the circuit breaker at both ends of a transmission line is achieved by

Carrier current over the power line provides simultaneous tripping of circuit breakers at both ends of the line in one to three cycles.
Thereby high-speed fault clearing is obtained, which improves the power system stability.
The auto-reclosing simultaneous reclosing signal is sent thereby simultaneous (1 to 3 cycles) reclosing of the circuit breaker is obtained.
For simultaneous faults, carrier-current protection provides easy discrimination.

As per answer key "pilot protection" is true but there is mistake the right answer is "none".

જ્યાં ઉપમેયનો ઉલ્લેખ જ કરવામાં ન આવે અને ઉપમાન જ ઉપમેય હોય ત્યારે દ્રષ્ટાંત અલંકાર બને છે. - આ કથન સત્ય છે કે નહિ અને જો ખોટું હોય તો સત્ય કથન કયું હોઈ શકે?

___ is the rms value of the total current comprising the AC and DC components of the current in the circuit breaker pole at the instant of contact separation.

Symmetrical breaking current:
It is the rms value of a a.c component of the current in the pole at the instant of contact separation.

Asymmetrical breaking current:
It is the rms value of the total current comprising the a.c and d.c components of the current in the pole at the instant of contact separation.