The resistance of a bulb filament is $100\,\Omega$ at a temperature of $100\,^{\circ}C$. If its temperature coefficient of resistance is $0.005\,^{\circ}C^{-1}$,at what temperature will its resistance become $200\,\Omega$?

The specific resistance (resistivity) of manganin is $50 \times 10^{-8} \, \Omega \cdot m$. The resistance of a cube of length $50 \, cm$ will be:

$A$ heating element using nichrome connected to a $230 \;V$ supply draws an initial current of $3.2 \;A$ which settles after a few seconds to a steady value of $2.8 \;A$. What is the steady temperature of the heating element if the room temperature is $27.0^{\circ} C$ (in $^{\circ} C$)? The temperature coefficient of resistance of nichrome averaged over the temperature range involved is $1.70 \times 10^{-4} \;^{\circ} C^{-1}$.

An electric wire of length $l$ and area of cross-section $a$ has a resistance $R \ \Omega$. Another wire of the same material having the same length and area of cross-section $4a$ has a resistance of:

The length of the resistance wire is increased by $10\%$. What is the corresponding change in the resistance of the wire? ................ $\%$

$A$ metal wire of specific resistance $64 \times 10^{-6} \, \Omega \cdot \text{cm}$ and length $198 \, \text{cm}$ has a resistance of $7 \, \Omega$. The radius of the wire will be ............. $\text{cm}$.