An ammeter and a voltmeter are joined in sereis to a cell. Their readings are `A` and `V` respectively. If a resistance is now joinding parallel with the voltmeter. Then

Options

A. both `A` and `V` will increase
B. both `A` and `V` will decrease
C. `A` will decrease, `V` will increase
D. `A` will increase, `V` will decrease

Answer

D

Explanation

When a resistance is connected in parallel to voltmeter, equivalent resistance of `R` and `R_V` is smaller than `R` or `R_V`, hence resistance of circuit decreases and therefore current in the circuit i.e., reading of ammeter increases `(A' gt A)`.
`V_A + V_V = E, V'_A + V'_V = E`
`V'_A gt V_A` (Since `A' gt A)`, hence`V'_V lt V_V`, reading of voltmeter decreases.