Question

A voltmeter of resistance 20000 ohm reads 5V. to make it to read 20V , the extra resistance required is
a)40000 ohm in parallel
b)60000 ohm in series
c)20000 ohm in series
d)80000 ohm in parallel

B is correct option. please explain

Answer 1

$\huge\boxed{HEY\:MATE!!}$

formula to be applied is

Rs = Rg(n-1)

where,

n is number of times voltage increased

and Rs is Shunt resistance

now,

n = 20/5 = 4

Rs = 20000(4-1)

Rs = 60000

✓✓ option B is correct

Answer 2

Explanation:

option B is correct answer