If $X, Y$ and $Z$ in the figure are identical lamps, which of the following changes to the brightnesses of the lamps occur when switch $S$ is closed?

X

stays the same,

Y

decreases

No worries! We‘ve got your back. Try BYJU‘S free classes today!

X

and

Y

increases

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

X

increases,

Y

stays the same

No worries! We‘ve got your back. Try BYJU‘S free classes today!

X

decreases,

Y

increases

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $X$ and $Y$ increases
In the given circuit, bulb X is in series with bulbs Y and Z parallel to each other. Thus when switch S is closed due to series combination voltage drops add to equal total voltage. Hence the power is equally shared in bulbs X and (Y Z) combination, this will increase the brightness of X.
Also, in parallel combination all bulbs share the same (equal) voltage. Hence equal power is consumed in Y and Z and they will bright same as X. Hence when switch S is closed brightness of bulbs X and Y increases.

Suggest Corrections

Similar questions

X

Y

Z

S

If $r_{x y}$ is positive the relation between X and Y is of the type

(a) when Y increases X increases

(b) when Y decreases X increases

If r_xyis positive the relation between X and Y is of the type

(i) When Y increases X increases

(ii) When Y decreases X increases

(iii) When Y increases X does not change

If y increases with an increase in x and y decreases with a decrease in x, then they are said to follow _______.

Join BYJU'S Learning Program