Questions

Number of spectral lines from a state n to ground state is

                   n(n-1)/2 = 6

F9 keystroke is used for updating a field.

In the given options, "His stomach rumbled like an approaching train" is an example of Simile.

All the other options are examples of metaphors. 

Simile and Metaphor are both figure of speeches in English which are used for comparing things but the only difference is Simile uses LIKE or AS words in comparing and metaphor directly compares without using any words.

The total angle traced by the hour hand is the angle traced in 7 hours and 10 minutes.
We know that the angle traced by the hour hand in one hour is 30º and in one minute is 1/2º.
Therefore, (30º x 7) + (10 x 1/2º) = 215º is the angle traced by the hour hand.

First nationalisation of commercial banks in India took place in 1969 and second time in 1980.

Here in the given puzzle,

2 x (2 + 2) = 8

3 x (3 + 3) = 18

4 x (4 + 4) = 32

5 x (5 + 5) = 50

Similarly,

6 x (6 + 6) = 72.