1.
A car starts from rest and moves with the velocity of 10m/s in 10 seconds.find its accelaration?
Correct Answer
B. 1m/s square
Explanation
The car starts from rest and reaches a velocity of 10m/s in 10 seconds. To find the acceleration, we can use the equation: acceleration = change in velocity / time taken. In this case, the change in velocity is 10m/s (from rest to 10m/s) and the time taken is 10 seconds. Therefore, the acceleration is 10m/s / 10s = 1m/s².
2.
Who stated the laws of motion?
Correct Answer
A. Issac newton
Explanation
Isaac Newton is credited with stating the laws of motion. His three laws of motion are fundamental principles in physics that describe the relationship between an object and the forces acting upon it. Newton's laws of motion revolutionized the field of physics and laid the foundation for understanding the motion of objects in the universe.
3.
Who made the alpha particle scattering experiment?
Correct Answer
C. Ernst Rutherford
Explanation
Ernst Rutherford made the alpha particle scattering experiment.
4.
An atom has a hard body inside it which carries the maximum weight of the atom.it is called?
Correct Answer
D. Nucleus
Explanation
The correct answer is nucleus. The nucleus is the central part of an atom that contains protons and neutrons, which have the maximum weight of the atom. The electrons orbit around the nucleus in energy levels, but they have negligible weight compared to the protons and neutrons. Therefore, the nucleus is responsible for carrying the maximum weight of the atom.
5.
What is universal gravitation constant?
Correct Answer
A. 9.8m/s square
Explanation
The universal gravitation constant, denoted by G, is a fundamental constant in physics. It is the proportionality constant that appears in Newton's law of universal gravitation, which states that the force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. The value of G is approximately 6.67430 × 10^-11 N(m/kg)^2. The given answer of 9.8m/s square is incorrect as it represents the acceleration due to gravity on Earth's surface, not the universal gravitation constant.
6.
Who said that atom is the smallest paricle of an element?
Correct Answer
B. Dalton
Explanation
Dalton is the correct answer because he proposed the atomic theory, which stated that atoms are the smallest particles of an element that cannot be divided further. This theory revolutionized the understanding of matter and laid the foundation for modern chemistry. Dalton's work was based on extensive research and experimentation, making him a significant figure in the field of atomic theory.
7.
Metals are -
Correct Answer
C. Both i and ii
Explanation
Metals are both sonorous and ductile. Sonorous means that metals produce a ringing sound when struck, indicating their ability to vibrate freely. Ductile refers to the property of metals to be stretched into thin wires without breaking. Therefore, both options i and ii are correct, as metals possess both sonorous and ductile characteristics.
8.
Define power?
Correct Answer
A. The rate of doing work
Explanation
The correct answer is "The rate of doing work." Power is defined as the rate at which work is done or the amount of work done per unit of time. It measures how quickly or efficiently work is being done. Therefore, option i is the correct definition of power. Option ii is incorrect as it only mentions the capacity of doing work, without considering the time aspect. Option iii is incorrect as it includes both correct definitions, and option iv is incorrect as it states that none of the above definitions are correct, which is not true.
9.
Buoyant force is-
Correct Answer
A. The upward force by any liquid
Explanation
The buoyant force is the upward force exerted by any liquid on an object immersed in it. This force is equal to the weight of the liquid displaced by the object. It is responsible for making objects float in a liquid.
10.
What are isotopes?
Correct Answer
B. The element having same atomic no.
Explanation
Isotopes are elements that have the same atomic number but different mass numbers. This means that they have the same number of protons in their nucleus but different numbers of neutrons. This results in isotopes having different atomic masses. For example, carbon-12 and carbon-14 are isotopes of carbon, as they both have 6 protons but different numbers of neutrons.