Given a current carrying wire of non-uniform cross-section. Which of the following is constant throughout the length of the wire?
(A) Current, electric field and drift speed
(B) Drift speed only
(C) Current and drift speed
(D) Current only
1 Answers
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The wire of length L and resistance R is stretched so that its radius of cross-section is halved. What is its new resistance?
Correct answer is (D) 16R
2 Answers 1 views
DC current flows in a metal piece of non uniform cross-section. Which of these quantities remains constant along the conductor
Drift velocity and current density will change as it depends upon area of cross-section whereas current will remain constant.
2 Answers 2 views
The diameter of a copper sphere is 18 cm. It is melted and drawn into a long wire of uniform cross section. If the length of the wire is 108 m, find i
Correct Answer - 0.6 cm
2 Answers 1 views
A wire of length 20 m and area of cross section 1.25 × 10^-4 m^2 is subjected to a load of 2.5 kg. (1 kg wt = 9.8 N).
L = 20 m, A = 1.25 × 10-4m2, F = mg = 2.5 × 9.8 N, l = 10-4 m Formula Y = \(\frac{FL}{Al}\) To find: Young’s modulus (Y) Calculation: From formula, Y = \(\frac{2.5\times9.8\times20}{1.25\times10^{-4}\times10^{-4}}\) = 3.92 × 1010Nm-2 The...
2 Answers 2 views
Calculate the strain energy per unit volume in a brass wire of length 3 m and area of cross-section 0.6 mm^2 when it is stretched by 3 mm
Given: L = 3 m, F = 6 kg wt = 6 × 9.8N = 58.8N, A = 0.6 mm2 = 0.6 × 10-6 m2, = 3 mm = 3 × 10-3 m To find: Strain energy...
2 Answers 1 views
A force of 100 N produces a change of 0.1% in a length of wire of area of cross section 1 mm^2. Young’s modulus of the wire is ____
Correct option is: (C) 1011 N/m2
2 Answers 1 views
A copper wire (Y = 1 × 10^11 N/m^2) of length 6 m and a steel wire (Y = 2 × 10^11 N/m^2) of length 4 m each of cross-section 10^-5 m^2 are fastened
Correct option is: (C) 0.6 mm
2 Answers 1 views
A current carrying wire of length L is placed perpendicular to a uniform magnetic field B.
Correct option is B) ILB
2 Answers 2 views
A negligibly small current is passed through a wire of length 15 m and uniform cross-section 6 × 10^-7 m^2, and its resistance is measured to be 5 Ω.
Given: l = 15 m, A = 6.0 × 10-7 m2, R = 5 Ω To find: Resistivity (ρ) Formula: ρ = \(\frac{RA}{l}\) Calculation: From formula, ρ = \(\frac{5\times6\times10^{-7}}{15}\) ∴ ρ = 2 × 10-7 Ω m
2 Answers 1 views
The current in the primary circuit of a potentiometer is `0.2 A`. The specific resistance and cross-section of the potentiometer wire are `4xx10^(-7)`
Correct Answer - C `V=irhol`
2 Answers 1 views