Physics objective questions, Test Series 4 with solutions - Newton’s Laws of Motion and Friction

Below is another set of 10 MCQ practice questions (Q.No.31 - 40) with hints & solutions (link given at the end) from the Physics chapter -Newton’s Laws of Motion and Friction. Physics test series, questions asked in NEET, JEE Main, Medical and Engineering Entrance Exams
Questions from some of these topics (randomly selected):
Force and Inertia; Law of Inertia; Newton’s First Law of Motion; Center of Mass; Momentum; Newton’s Second Law of Motion; Impulse; Newton’s Third Law of Motion; Law of Conservation of Linear Momentum and its applications; Variable Mass; Free Body Diagrams; Pulleys; Equilibrium of Concurrent Forces; Constraint Equations; Pseudo Force; Static and Kinetic Friction; Laws of Friction; Rolling Friction; Centripetal Force and its applications; Impulse; Collision

Newton’s Laws of Motion and Friction

India Study Solution MCQ Test Series – Set 4 (Q. No 31-40)

Question 31: When a constant force is applied to a body, it moves with uniform:
a. Acceleration
b. Velocity
c. Speed
d. Momentum

Question 32: A box ‘A’ is lying on the horizontal floor of the compartment of a train running along horizontal rails from left to right. At time ‘t’, it decelerates. Then the reaction R by the floor on the box is given best by:

Physics MCQ Test Series 4 Question No 32 with solution - Newton’s Laws of Motion and Friction
Question 33: A lift of mass 1000 kg is moving upwards with an acceleration of 1m/s2. The tension developed in the string, which is connected to lift? (g = 9.8m/s2)
a. 9800 N
b. 10800 N
c. 11000 N
d. 10000 N

Question 34: A body of mass 1 kg rests on a smooth surface. Another body B of mass 0.2 kg is placed over A as shown. The coefficient of static friction between A and B is 0.15. B will being to slide on A if a pulled with a force greater than –
Newton’s Laws of Motion and Friction - India Study Solution Test Series 4 Question No 34 image

Question 35: If the coefficient of friction of a plane inclined at 300 is 0.4, then the acceleration of the body sliding freely on it, is: (g = 9.8m/s2)
a. 1. 51 m/s2
b. 3. 54 m/s2
c. 9.8 m/s2
d. 4.9 m/s2

Question 36: A marble block of mass 2 kg lying on ice when given a velocity of 6m/s is stopped by friction in 10 s. Then, the coefficient off friction is:
a. 0.02
b. 0.03
c. 0.06
d. 0.01

Question 37: A block is moving up an inclined plane of inclination θ = 300 with a velocity 5 m/s. If it stops after 0.5 s then what is the value of coefficient of friction (µ) ?
Newton’s Laws of Motion and Friction - India Study Solution Test Series 4 Question No 37 - image

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Question 38: A man getting down a running bus, fails forward because –
a. Due to inertia of rest, road is left behind and man reaches forward
b. Due to inertia of motion upper part of body continues to be in motion in forward direction while feet come to rest as soon as they touch the road
c. He leans forward as a matter of habit
d. Of the combined effect of all the three factors stated in a, b and c

Question 39: A dynamometer D, is connected with two bodies of mass M = 6 kg and m = 4 kg. If two forces F = 20 N and F = 10 N are applied on masses according to figure then reading of the dynamometer will be –
a. 10 N
b. 20 N
c. 6 N
d. 14 N

Question 40: Two masses M1 and M2 connected by means of a string which is made to pass over light, smooth pulley are in equilibrium on a fixed smooth wedge as shown in figure. If θ = 600 and α = 300, the ratio of M1 to M2 is –

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Biology Guide for NEET, MBBS admission tests: Breathing and Respiration, Exchange of Gases - very long answer questions

HUMAN PHYSIOLOGY (Breathing and Respiration, Exchange of Gases)

Biology (Zoology) Very Long Answer Theoretical Questions - TQ5 (Q. No.72-75)
Solved Very Long Answer Biology Questions (Zoology)
Question 72:  How does the exchange of gases occur in respiration between blood and alveolar air?
Answer 72: The exchange of gases (i.e., oxygen and carbon dioxide) between lung alveoli and pulmonary capillaries is called external respiration. It occurs as follows: - Breathing and Respiration images
The wall of the alveoli is very thin and has rich network of blood capillaries. Due to this, the alveolar wall seems to be a sheet of flowing blood and is called respiratory membrane. The respiratory membrane consists mainly of (a) alveolar epithelium, (b) epithelial basement membrane, (c) a thin interstitial space (d) capillary basement membrane and (e) capillary endothelium. All these layers form a membrane of 0.2 mm thickness. The respiratory membrane has a limit of gaseous exchange between alveoli and pulmonary blood. It is called diffusing capacity. The diffusing capacity is defined as the volume of gas, that diffuses through the membrane per minute for a pressure difference of 1 mm Hg. It is further dependent on the solubility of the discussing gases. In other words, at the particular pressure difference, the diffusion of carbon dioxide is 20 times faster than oxygen and that of oxygen is two times faster than nitrogen. The partial pressure of oxygen (PO2) in the alveoli is higher (104 mm Hg) than that in the deoxygenated blood in the capillaries of the pulmonary arteries (95 mm Hg). As the gases diffuse from a higher to a lower concentration, the movement of oxygen us from the alveoli to the blood. The reverse is the case in relation to carbon dioxide. - Breathing and Respiration images
The partial pressure of carbon dioxide (PCO2)  is higher in deoxygenated blood (45 mm Hg) than in alveoli (40 mm Hg), therefore, carbon dioxide passes from the blood to the alveoli. The partial pressure of nitrogen (PN2) is the same (537 mm Hg) in the alveoli as it is in the blood. This condition is maintained because nitrogen as a gas is not used up by the body. - Breathing and Respiration, Exchange of Gases images
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Question: 73: Discuss the transport of gases (O2 and CO2) in the blood.
Answer 73: Transport of Oxygen in the Blood: Blood carries oxygen from the lungs to the heart and from the heart to various body parts. Oxygen is transported in the following manners:
1. As dissolved gas: About 3% of oxygen in the blood is dissolved in the plasma which carries oxygen to the body cells.
2. As oxyhaemoglbin: About 97% of oxygen is carried in combination with haemoglobin of the erythrocytes. Haemoglobin (Hb) consists of a protein called globin and a pigment portion called heme. The heme portion contains four atoms of iron, each capable of combining with a molecule of oxygen. Oxygen and haemoglobin combine in an easily reversible reaction to form oxyhaemogloin (HbO2).       Hb + 4O2         Hb (O2)4
Under the high partial pressure, oxygen easily binds with haemoglobin in the pulmonary (lung) blood capillaries. When this oxygenated blood reaches the different tissues, the partial pressure of oxygen declines and the bonds holding oxygen to haemoglobin become unstable. As a result, oxygen is released from the blood capillaries.
Oxygen-haemoglobin Dissociation Curve: The amount of oxygen that can bind with haemoglobin is determined by oxygen tension. This is expressed as partial pressure of oxygen (PO2). The percentage of haemoglobin that is bound with O2 is called percentage saturation of haemoglobin. The relationship between the partial pressure of oxygen (PO2) and percentage saturation of the haemoglobin with oxygen (O2) is graphically illustrated by a curve called oxygen-haemoglobin dissociation curve (also called oxygen dissociation curve).Under normal conditions, the oxygen-haemoglobin dissociation curve is sigmoid shaped or "S" shaped. - Breathing and Respiration, Exchange of Gases images
Factors affecting oxygen-haemoglobin dissociation curve: It is shifted either to left or right by various factors-
1. Shift to Right: Shift to right indicates dissociation of oxygen from haemoglobin.
2. Shift to Left: Shift to left indicates acceptance (association) of oxygen by haemoglobin.
3. Bohr Effect: Shifting of the oxygen haemoglobin dissociation curve to the right by increasing carbon dioxide partial pressure is known as Bohr Effect.
Transport of carbon dioxide: In the oxidation of food, carbon dioxide, water and energy are produced. Carbon dioxide in gaseous form diffuses out of the cells into the capillaries, where it is transported in  three ways-
(a). Through blood plasma: Carbon dioxide is transported through this medium in a very little quantity. CO2 combines with water of plasma in presence of carbonic anhydrase enzyme to form carbonic acid.
This soon dissociate into H+ and HCO3-ions. Very little % of CO2 is transported through this method as increased production of carbonic acid increases pH from 7.4 - 4.0.
CO2 + H2O <------> H2CO3  <-----> H+ + HCO3-
(b). By haemoglobin: CO2 combines with haemoglobin to form carbaminohaemoglobin.
Hb + CO2 <-----> HbCO2 
About 30% of CO2  is transported by above 2 methods.
(c). As bicarbonates: About 70% of CO2 is transported   as bicarbonates. Initially, in the RBC potassium haemoglobin dissociates  into K+ + Hb.CO2 when diffuses in the RBC  combines with water of the cytoplasm to form carbonic acid which dissociates into H+ and HCO3-ions. Haemoglobin combine with H+ ions to form haemoglobin acid. While in the plasma same CO2 combines worth water of the plasma to form carbonic acid which forms H+ and HCO3-ions. NaCl dissociates into Na+ + Cl-.
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Question: 74: Describe how the contraction and relaxation of some skeletal muscles produce respiratory movements.
Answer 74: During exercise forceful expiration take place in which with relaxation inspiratory muscles, contraction of expiratory or respiratory muscles takes place. These muscles are of two place:
1. Abdominal muscles
When abdominal muscles contract, visceral organs of abdominal cavity push diaphragm upwards. So, it become more dome shape. When IICM contract ribs and sternum shift downward and inward. By contraction in both muscles volume of thoracic cavity decrease more and intrapulmonary pressure increase more, so, more expiration occur through respiratory tract called forceful expiration.
Question: 75: Write in detail about various respiratory disorders.
Answer 75: Various respiratory disorders are as follows-
Bronchial Asthma: It is an allergy caused by some allergens like pollen grain, dust particle. Allergen stimulate mast cells to produce histamine that causes contraction of smooth muscles of bronchi. Symptoms-coughing, difficulty in breathing mainly during expiration, breathing with wheezing sound, excess mucus secretion from respiratory tract that may clog bronchi and bronchiole.
Emphysema: Emphysema is an abnormal distension of bronchi, bronchiole and alveolar sac of the lungs mainly due to cigarette smoking. Tifr sepia between alveoli are dissolves and elastic tissue replaced by fibrous connective tissue so that lung become non-elastic. Respiratory surface of lung reduced, bronchiole become non-elastic, alveoli remain filled with air even after exhalation.
Bronchitis: Inflammation of the bronchi due to cigarette smoking, air pollutant like CO and Microbial infection.
Pneumonia: It is an acute infection and inflammation of the lung alveoli by S.pneumonae, Mycoplasma, and some false yeast. Infant, young ones, HIV patient are more sensitive for pneumonia. Symptoms- The alveoli becomes acutely inflammated, most of the air space filled with mucus and fluid with WBC.
Occupational lung diseases: These disorders are caused due to exposure of potentially harmful substances, such as gas, fumes or dusts, present in the environment where a person works.
(a). Silicosis and asbestosis: These are common examples, which occur due to chronic exposure of silica and asbestos dust in the mining industry.
(b). Pneumoconiosis: It is found in coal workers.
(c). Byssinosis: It is found in workers of cotton industry.
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Breathing and Respiration, Exchange of Gases - long answer questions for Entrance Exams and Admission Tests

Breathing and Respiration, Exchange of Gases
Covering Syllabus: Respiratory organs in animals (recall only); Respiratory system in humans; Mechanism of breathing and its regulation in humans-Exchange of gases, transport of gases and regulation of respiration Respiratory volumes; Disorders related to respiration-Asthma, Emphysema, Occupational respiratory disorders.

HUMAN PHYSIOLOGY (Breathing and Respiration, Exchange of Gases)

Biology (Zoology) Long Answer Theoretical Questions - TQ 4 (Q. No.68-71)
Solved Long Answer Type Biology Questions (Zoology)
Question: 68: Write the role of diaphragm in the breathing process.
Solution 68: 
Breathing:  Intake of fresh air from environment and expulsion of fowl air from lungs is called breathing, so there are two steps in breathing:
1.       Inspiration
2.       Expiration
1.       Intake of fresh air.
2.       It is an active process.
3.       Completes in 2 sec.
Inspiration occurs by contraction in inspiratory muscles, which are of two types:
(i). Radial muscles of diaphragm.
(ii). EICM. 
When radial muscles contract diaphragm become flattened in shaped so volume of thoracic cavity increase between anterior and posterior surface.
When EICM contract sternum comes outward and ribs goes upward. By the contraction in both muscles volume of thoracic cavity increase and intrapulmonary pressure, decrease by 1-3 mm Hg. Therefore, environmental air enters into lungs through respiratory tract called inspiration. 
1.       Expulsion is flow of air.
2.       It is a passive process.
3.       It takes 3 sec.
4.       Expiration occurs by relaxation in inspiratory muscles.
5.       By relaxation in radial muscles diaphragm become normal dome- shape.
6.       When EICM relax, then ribs and sternum comes to their normal position.

So, by relaxation on both muscles volume of thoracic cavity decrease and intrapulmonary pressure increase by 1-3 mm Hg. Therefore, expulsion of air occurs through respiratory tract called expiration.

Question: 69: What is partial pressure? How does it help in gaseous exchanges during respiration?
Solution 69: The pressure of a particular gas among the pressure of all the gases is called partial pressure. Gases move according to the pressure gradient from the higher partial pressure to lower partial pressure as follows - image
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Question: 70: What is chloride shift?
Solution 70:  As more carbon dioxide enters into the RBC, concentration of bicarbonates in RBC is more than in plasma. Thus bicarbonate ions diffuse quickly from the RBCs into the plasma, where they are carried to the lungs. To counter balance the rapid outrush of negative bicarbonate ions from the RBCs, chloride ions (Cl) move from the plasma into the erythrocytes. This ionic exchange process is called the Chloride Shift. After the chloride shift, potassium bicarbonate and potassium chloride are formed in the RBC while NaCl and NaHCO3 are formed in the plasma. - graphics showing transportation of CO2 between tissue cell and tissue blood capillary

In the lungs, the process is reversed. As blood moves through the pulmonary capillaries, its PCO2 declines from 45 mm Hg to 40 mm Hg (and respectively from 54 vol% to 49 vol%). For this to occur, carbon dioxide must first be freed from its “bicarbonate housing.” Bicarbonate ions re-enter the RBCs (and chloride ions move into the plasma) and bind with hydrogen ions to form carbonic acid, which is then split by carbonic anhydrase to release carbon dioxide and water. This carbon dioxide, along with that released from haemoglobin and from solution in plasma, and then diffuses along its partial pressure gradient from the blood into the alveoli. This total process is referred as Hamburger phenomena.    

Question: 71: Explain the terms: tidal volume, vital capacity and residual volume in relationship to respiration.
Solution 71: VC = IRV + ERV + TV
= 3000 + 1100 + 500
= 4600 ml.   
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Work, Energy and Power - Solved Test Series, Questions Bank for NEET, AIIMS, JEE Main and Advanced, NEST, Admission Tests

India Study Solution - Physics Guide 

Work, Energy and Power

In continuation of Test Series Set 1 (Q. No. 1-10) and Test Series Set 2 (Q. No. 11-20), here you have carefully selected 10 MCQ practice questions with hints & solutions (given at the end) from the Physics chapter - Work, Energy and Power.

Syllabus for IITJEE, NEET:                                                                      
Work done by a constant force and by a variable force, Unit of Work, Energy and Power, Work Energy, Theorem. Elastic and in-elastic collisions in one and two dimensions, Notions of Work and Energy, Law of Conservation of Energy, Potential and Kinetic Energies, Gravitational Potential Energy, and its conversion to Kinetic energy, Potential Energy of a spring. Conservative and Non-conservative Forces, Different forms of Energy, Three types of Equilibrium, Mass-Energy equivalence. Power.   
Solved MCQ Test Series – Set 3 (Q. No. 21-30)
Question 21: A particle is projected at 60O to the horizontal with a kinetic energy K. The kinetic energy at the highest point is,  
a. K     b. Zero
c. K/4  d. K/2  

Question 22: Two springs with spring constants k1 and k2 (k1 ¹ k2) are extended by the same force. If their elastic potential energies are U1 and U2, then, U2 will be -

Question 23: A particle of mass 0.1kg is subjected to a force that varies with distance as shown in the adjacent diagram. If the particle starts its journey from rest at x = 0, its velocity at x = 12m will be -
a. 0 m/s           b. 20√2 m/s  
c. 20√3 m/s     d. 40 m/s  

Question 24: A ball released from a height 20m, hits the ground and rebounds to a height of 16m. The percentage loss of energy during collision is, 
a. 20%  b. 40%  c. 25%  d. 75%.  

Question 25: A block of mass 50kg is projected horizontally on a rough horizontal floor. The coefficient of friction between the block and the floor is 0.1. The block strikes a light spring of stiffness k = 100N/m with a velocity 2m/s. The maximum compression of the spring is,  
a. 1m    b. 2m
c. 3m    d. 4m  

Question 26: A uniform meter scale of mass 2kg is suspended from one end. If it is displaced through an angle 60O from the vertical, the increase in its potential energy is,  
a. 4.9J   b. 9.8J   c. 9.8√3J   d. 4.9(2 – √3)J  

Question 27: A rigid body of mass ‘m’ is moving in a circle of radius ‘r’ with a constant speed ‘v’. The force on the body is mv2/r and is directed towards the center. What will be the work done by this force in moving the body over half the circumference of the circle.

Question 28: A ball ‘A’ is released from rest when the block ‘B’ is on the ground (see adjacent fig.). For the block ‘B’ of mass ‘M’ to remain in contact with ground, the minimum mass of ‘A’ must be -

a. 2M     b. M
c. M/2    d. None of these.  

Question 29: A body of mass 1kg is thrown upwards with a velocity 20ms–1. It momentarily comes to rest after attaining a height of 18m. How much energy is lost due to air friction? (g = 10ms–2)  
a. 20J    b. 30J
c. 40J    d. 10J  

Question 30: A ball is released from certain height and rebounds after hitting the ground. If it loses 50% of its KE on striking the ground then it will attain a height again equal to -
a. one fourth of the initial height
b. three fourth of the initial height
c. half of the initial height
d. none of these.  
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