1. Which of the following laws is associated with the heating effect of electric current ? Joule's law Ohm's law Faraday's law Newton's law Answer: Joule's law Explanation: Joule's law is associated with the heating effect of electric current. It is a way to find the amount of heat produced by electric current. H=I2Rt is the relation used to calculate heat generated View Answer Discuss in Forum Report Question

 2. The value of acceleration due to gravity ‘g’ depends on: 1. Constant of Gravitation ‘G’ 2. Mass of the earth ‘M’ 3. Mass of the falling object ‘m’ 4. Radius of the earth ‘R’ ? a, c, d b, c, d a, b, c a, b, d Answer: a, b, d Explanation: According to formula the acceleration due to gravity (g) is given by = GM/r2 View Answer Discuss in Forum Report Question

 3. Which element in the periodic table forms maximum number of compounds ? H O S C Answer: C Explanation: Carbon forms the maximum number of compounds in the periodic table. Since carbon has the property of tetra valency and catenation so they can form a maximum number of compounds. Carbon exists in several allotropic forms. Graphite and diamond are examples of allotropes of carbon that have different properties View Answer Discuss in Forum Report Question

 4. A body at rest can have ? Speed Velocity Momentum Energy Answer: Velocity Explanation: Therefore, a body at rest stores energy here, which is called potential energy. Momentum- The momentum of any object that is at rest is zero. Objects at rest do not have momentum as they do not have any "mass in motion". Both variables - mass and velocity - are important for calculating momentum View Answer Discuss in Forum Report Question

 5. A solid metallic hemisphere with radius r is melted and cast into a solid right circular cone with the radius of the base = r. What is the ratio of their curved surface areas ? 5/?2 2/?5 3/2 5/2 Answer: 2/?5 Explanation: Volume of hemisphere = (2/3)?r Volume of cone = (1/3)?r h According to the question (1/3)?r h = (2/3)?r h = 2r As we know, l = r + h ? l = r + (2r) ? l = 5r ? l = ?5 r Curved surface area of hemisphere = 2?r Curved surface area of cone = ?rl = ?r × (?5r) = ?5r Required ratio = 2?r /?5?r = 2/?5 View Answer Discuss in Forum Report Question

 6. How much work is done in moving a charge of 5 C across two points having a potential difference of 16 V ? 65 J 45 J 40 J 80 J Answer: 80 J Explanation: Electric charge (q) = 5 C difference (V) = 16 V Work done (W) = charge (q) × potential difference (V) Work done (W) = 5 × 16 = 80 J View Answer Discuss in Forum Report Question

 7. Which of the following statements is true ? Carbon monoxide diffuses from lungs into blood and oxygen diffuses from blood into lungs Carbon dioxide diffuses from lungs into blood and oxygen diffuses from blood into lungs Oxygen diffuses from lungs into blood and carbon dioxide diffuses from blood into lungs Oxygen diffuses from lungs into blood and carbon monoxide diffuses from blood into lungs Answer: Oxygen diffuses from lungs into blood and carbon dioxide diffuses from blood into lungs Explanation: View Answer Discuss in Forum Report Question

 8. Mendeleev could not assign a correct position to which of the following elements in his table ? Lithium Potassium Hydrogen Helium Answer: Hydrogen Explanation: The position of hydrogen was not justified in Mendeleev's periodic table. He positioned hydrogen in the first column above alkali metal. Hydrogen resembles not only alkali metals but also halogens in several ways. Hence, hydrogen can also be placed above the halogen group View Answer Discuss in Forum Report Question

 9. The atmospheric pressure at sea level is ........ atm ? 0.001 1 0 0.1 Answer: 1 Explanation: The atmospheric pressure at sea level is 1 atm View Answer Discuss in Forum Report Question

 10. Who demonstrated that objects of different masses would reach the ground together when dropped from the same height ? Isaac Newton Archimedes Robert Boyle Galileo Galilei Answer: Galileo Galilei Explanation: According to Galileo Galilei, if objects of different masses are dropped from the same height in the absence of air resistance the bodies will ground together at the same time View Answer Discuss in Forum Report Question