1) A resistor has following bands: red, brown, blue and silver. Its resistance lies between
1) $(189 M \Omega)$ to $(231 M \Omega)$
2) $(1.89 M \Omega)$ to $(2.31 M \Omega)$
3) $(18.9 M \Omega)$ to $(23.1 M \Omega)$
4) $(20 M \Omega)$ to $(22 M \Omega)$
Hint: Red $(\rightarrow 2)$ Brown $(\rightarrow 1)$ Blue $(\rightarrow 6)$ Silver $(\rightarrow 10 \%)$ $(R=21 \times 10^{6} \pm 10 \%=21 M \Omega \pm 10 \%)$ $$ \begin{aligned} & =(21 \pm \frac{10}{100} \times 21) M \Omega=(21 \pm 2.1) M \Omega \\ & =18.9 M \Omega \text { to } 23.1 M \Omega \end{aligned} $$
2) Bands on a resistor have colours green, grey, brown and silver. The value of the resistance is
1) $(470 \pm 10 \%)$
2) $(58 \pm 10 \%)$
3) $(580 \pm 10 \%)$
4) $(5800 \pm 5 \%)$
Hint: Green $(\rightarrow 5)$ Gray $(\rightarrow 8)$ Brown $(\rightarrow 1)$ $(R=(58 \times 10^{1}) \pm 10 \%=(580 \Omega \pm 10 \%))$
3) A resistor having bands red, green and orange is connected to a potential difference of 100 V . The current through it is
1) 4 mA
2) 40 mA
3) $(0.4 \mu A)$
4) $(4 \mu A)$
Hint: Red $(\rightarrow 2)$ Green $(\rightarrow 5)$ Orange $(\rightarrow 3)$ $(R=25 \times 10^{3} \Omega)$ $(i=\frac{V}{R})$ $(=\frac{100}{25000})$ $(=4 \times 10^{-3} A=4 mA)$
4) A given resistor has the following colour scheme of the various strips on it: Brown, Black, Green and Silver. Its value is
1) $(1.0 \times 10^{4} \Omega \pm 10 \%)$
2) $(1.0 \times 10^{5} \Omega \pm 10 \%)$
3) $(1.0 \times 10^{6} \Omega \pm 10 \%)$
4) $(1.0 \times 10^{7} \Omega \pm 10 \%)$
Hint: Numbers attached for Brown, Black, Green and Silver are $(105 \pm 10 \%)$. $(R=10 \times 10^{5} \Omega \pm 10 \%=1.0 \times 10^{6} \Omega \pm 10 \%)$