If the resistance `R_(1)` is increased (see figure), how will the reading of the ammeter and voltmeter change ?

Explanation

Consider the circuit in fig. (b) to find the change in reading
As we know the formula for base current, `I_(B) = (V_(BB) - V_(BE))/(R_(1))`

As `R_(i)` is increased, `I_(B)` is decreased.
Now, the current in ammeter is collector current `I_(C)`.
`I_(C) = beta I_(B) " as " I_(B)` decreased `I_(C)` also decreased and the reading of voltmeter and ammeter also decreased.