Resistance and Resistivity

Q. Resistivity is independent of

1. length of the material
2. Cross section area of the material
3. Nature of the material
4. both (a) and (b)

Q. The volume occupied by $4.75\text{g}$ of acetylene gas at ${50}^C$ and $750\text{mm Hg}$ pressure is \text{L}\).
(Round off to the nearest integer)
(Given, $R=0.0826{\text{L atm K}}^{-1}{\text{mol}}^{-1}$).

Q. Rajat, Sarath and Komal decided to measure resistance of aluminium and took bars of aluminium separately and measured its resistance in same room but got different values of resistance, of same material aluminium. What can be the probable reasons for these variations in resistance for same material?

1. All of the above
2. both length and cross section area of bars were different
3. they took bars of same cross section area but different length.
4. they took bars of same length but different cross section area

Q. A $0.1M$ solution of a monobasic acid has a specific resistance of ‘r’ Ωcm, its molar conductivity is:

1. 10/r
2. 10 r
3. ${10}^4/r$
4. ${10}^4$ r

Q. Column II gives name of material use for device given in column I :

Q. The resistance of a conductivity cell containing $0.001MKCl$ solution at $298K$ is $1500\Omega$. What is the cell constant if conductivity of $0.001MKCl$ solution at $298K$ is $0.146\times {10}^{-3}Sc{m}^{-1}$.

Q. A solution of sodium chloride discharges $6.1\times {10}^{16}N{a}^{+}$ ions and $4.6\times {10}^{16}C{l}^{-}$ ions in 10 seconds. Find the current passing through the solution.

1. 1.7 mA
2. 1.9 mA
3. 1.8 mA
4. 1.6 mA

Q. The specific conductance of $0.1N$ $KCl$ solution at ${23}^{o}C$ is $0.012{ohm}^{-1}{cm}^{-1}$. The resistance of cell containing the solution at the same temperature was found to be $55$ ohm. The cell constant will be:

1. $0.142{cm}^{-1}$
2. $0.918{cm}^{-1}$
3. $1.12{cm}^{-1}$
4. $0.66{cm}^{-1}$

Q. Which modifications are necessary to determine resistance of solutions by usual method of conductance measurement?

1. A.C. should be used
2. A conductivity cell is used
3. Galvanometer is replaced by headphone or magic eye arrangement
4. None of the above

Q. The filament resistance of bulb is ......, to its resistance when it is not glowing.

1. greater
2. lower
3. equal
4. none of above.