General Science - Online Test
Q1. A man of mass 70 kg stands on a weighing scale in a lift which is moving upwards with a uniform speed of 10 m , what would be the reading on the scale?
Answer : Option D
Explaination / Solution:
Mass of the man, m = 70 kg
Acceleration, a = 0
UsingNewton’s second law of motion,
wecan write the equation of motion as:
R – mg = ma
Where, ma is the net force acting on the man.
As the lift is moving at a uniform speed, acceleration a = 0
∴ R = mg = 70 × 10 = 700 N
∴ Reading on the weighing scale = 700 / g = 700 / 10 = 70 kg
Q2. Aging will be characterised by :
Answer : Option B
Explaination / Solution:
Aging will be characterized by decreased muscle size and increased muscle fat. With aging muscle loose its contractile and elasticity nature. Fats are deposited in muscle fibres the further decrease contracting ability.
Q3. Some ethical standards are required to
Answer : Option D
Explaination / Solution:
The manipulation of living organisms by the human race cannot go on any further, without regulation. Some ethical standards are required to evaluate the morality of all human activities that might help or harm living organisms.
Going beyond the morality of such issues, the biological significance of such things is also important. Genetic modification of organisms can have unpredicatable results when such organisms are introduced into the ecosystem.
Q4. The oxidation number of an element in a compound is evaluated on the basis of certain rules. Which of the following rules is not correct in this respect?
Answer : Option C
Explaination / Solution:
as oxygen is more electronegative than Cl,Br and I. So they have positive oxidation state.
Q5. The most important step to overcome the problem of population explosion is to
Answer : Option D
Explaination / Solution:
The problem of population explosion can be overcome by motivating smaller families by using contraceptive methods.
Q6. When pyridine is treated with a mixture of nitric and sulfuric acids, the major product is:
Answer : Option B
Explaination / Solution:
In pyridine EAS take splace at 3 position.
Q7. Stock is a concept which
Answer : Option D
Explaination / Solution:
No Explaination.
Q8. Which of these is not a fundamental force?
Answer : Option B
Explaination / Solution:
There are four conventionally accepted fundamental interactions—gravitational, electromagnetic, strong, and weak. Each one is described mathematically as a field.
Q9. The action of the dielectric to increase the capacitance is due to
Answer : Option D
Explaination / Solution:
When a dielectric is placed between the plates of a capacitor, electric polarization results in a reverse electric field inside the dielectric.
The net electric field reduces and therefore the potential reduces. Sincethe capacitance increases because the potential reduces.The charges in a dielectric are incapable of moving since all dielectrics are essentially insulators. The molecules of the dielectric acquire an induced dipole moment in the direction of the applied field, due to rearrangement of their electron clouds.The charges in the dielectric and those on the capacitor plates are not equal in magnitude. They are not neutralized. The dipoles in the dielectric are oriented perpendicular to the plates as the electric field is perpendicular to the plates.
The net electric field reduces and therefore the potential reduces. Sincethe capacitance increases because the potential reduces.The charges in a dielectric are incapable of moving since all dielectrics are essentially insulators. The molecules of the dielectric acquire an induced dipole moment in the direction of the applied field, due to rearrangement of their electron clouds.The charges in the dielectric and those on the capacitor plates are not equal in magnitude. They are not neutralized. The dipoles in the dielectric are oriented perpendicular to the plates as the electric field is perpendicular to the plates.
Q10. The molarity of NaOH in a solution prepared by dissolving its 4.0 g in enough water to form 250 mL of the solution is ,
Answer : Option C
Explaination / Solution:
Since , Molarity
=
substituting the given values , we get -
Molarity ( M )
=
=0.4M
* moles of solute ie. NaOH = mole
.= 0.1mol
