A wire 50 cm long and 1 mm2 in cross-section carries a current of 4 A when connected to a 2 V battery. The resistivity of the wire is

Question

A wire 50 cm long and 1 mm2 in cross-section carries a current of 4 A when connected to a 2 V battery. The resistivity of the wire is (A) 2 × 10-7 Ω m (B) 5 × 10-7 Ω m (C) 4 × 10-6 Ω m (D) 1 × 10-6 Ω m

Tardigrade Admin · Accepted Answer

Length (l)=50 cm =0.5 m; Area (A)=1 mm 2=1 × 10-6 m 2; Current (I)=4 A and voltage (V)=2 volts. Resistance (R)=(V/I)=(2/4)=0.5 Ω and Resistivity (ρ) =R × (A/l)=0.5 × (1 × 10-6/0.5) =1 × 10-6 Ω . m .

Q. A wire $50 c m$ long and $1 m m^{2}$ in cross-section carries a current of $4 A$ when connected to a $2 V$ battery. The resistivity of the wire is

$2 \times 1 0^{- 7} Ω m$

$5 \times 1 0^{- 7} Ω m$

$4 \times 1 0^{- 6} Ω m$

$1 \times 1 0^{- 6} Ω m$

Q. A wire 50cm long and 1mm2 in cross-section carries a current of 4A when connected to a 2V battery. The resistivity of the wire is

2×10−7Ωm

5×10−7Ωm

4×10−6Ωm

1×10−6Ωm

Length (l)=50cm=0.5m; Area (A)=1mm2=1×10−6m2; Current (I)=4A and voltage (V)=2 volts. Resistance (R)=IV​=42​=0.5Ω and Resistivity (ρ)=R×lA​=0.5×0.51×10−6​ =1×10−6Ω.m.

Q. A wire $50 c m$ long and $1 m m^{2}$ in cross-section carries a current of $4 A$ when connected to a $2 V$ battery. The resistivity of the wire is

$2 \times 1 0^{- 7} Ω m$

$5 \times 1 0^{- 7} Ω m$

$4 \times 1 0^{- 6} Ω m$

$1 \times 1 0^{- 6} Ω m$