Three bulbs of $$40 \mathrm{~W}, 60 \mathrm{~W}$$, and $$100 \mathrm{~W}$$ are arranged in series with a $$220 \mathrm{~V}$$ source. The maximum light is obtained from

The resistance of a $$10 \mathrm{~m}$$ long wire is $$10 \Omega$$. Its length is increased by $$25 \%$$ by stretching the wire uniformly. The new resistance is

Four resistors, each of resistance R, are connected as shown in the figure below.

A voltmeter of resistance $$1000 \Omega .0 .5 \mathrm{~V} /$$ div is to be converted into a voltmeter to make it to read $$=1 \mathrm{~V} / \mathrm{div}$$. The value of high resistance to be connected in series with it is