The Young's modulus of steel is twice that of brass. Two wires of same length and of same area of cross-section, one of steel and another of brass are suspended from the same roof. If we want the lower ends of the wires to be at the same level, then the weight added to the steel and brass wires must be in the ratio of

(a)1:2

(b)2:1

(c)4:1

(d)1:1

Concept Questions :-

Stress-strain
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Copper of fixed volume V is drawn into wire of length l. When this wire is subjected to a constant force F, the extension produced in the wire is  Δl. Which of the following graphs is a straight line?

(a)Δl versues 1/l

(b)Δl versus l2

(c)Δl versus 1/l2

(d) Δl versus l

Concept Questions :-

Hooke's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The following four wires are made of the same material. Which of then will have the largest extension when the same tension is applied?

(a) Length=50cm, diameter=0.5mm

(b) Length=100cm, diameter=1mm

(c) Length=200cm, diameter=2mm

(d) Length=300cm, diameter=3mm

Concept Questions :-

Hooke's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The Young's modulus of a wire of length L and radius r is If the length and radius are reduced to L/2 and r/2, then its Young's modulus will be -

(a) 1:1                           (b) 1:4

(c) 1:8                             (d) 8:1

Concept Questions :-

Stress-strain
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

When a certain weight is suspended from a long uniform wire, its length increases by one cm. If the same weight is suspended from another wire of the same material and length but having a diameter half of the first one then the increase in length will be -

(a) 0.5 cm                              (b) 2 cm

(c) 4 cm                                 (d) 8 cm

Concept Questions :-

Hooke's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The area of cross-section of a wire of length 1.1 metre is 1$m{m}^{2}.$It is loaded with 1 kg. If Young's modulus of copper is $1.1×{10}^{11}N/{m}^{2},$ then the increase in length will be (If $g=10m/{s}^{2}$)

(a) 0.01 mm                (b) 0.075 mm

(c) 0.1 mm                  (d) 0.15 mm

Concept Questions :-

Hooke's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In CGS system, the Young's modulus of a steel wire is  . To double the length of a wire of unit cross-section area, the force required is

(a) $4×{10}^{6}$dynes                     (b) $2×{10}^{12}dynes$

(c) $2×{10}^{12}newtons$                (d) $2×{10}^{8}$dynes

Concept Questions :-

Hooke's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The material which practically does not show elastic after effect is

(a) Copper                          (b) Rubber

(c) Steel                             (d) Quartz

Concept Questions :-

Elasticity
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A force F is needed to break a copper wire having radius R. The force needed to break a copper wire of radius 2R will be

(a) F/2                                      (b) 2F

(c) 4F                                       (d) F/4

Concept Questions :-

Stress-strain
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The relationship between Young's modulus Y, Bulk modulus K and modulus of rigidity n is

(a) $Y=\frac{9nK}{n+3K}$                                    (b) $\frac{9YK}{Y+3K}$

(c)  $Y=\frac{9nK}{3+K}$                                     (d) $Y=\frac{3nK}{9n+K}$

Concept Questions :-

Stress-strain