General Science - Online Test
Q1.
In the above experimental set up for studying photoelectric effect, if keeping the frequency of the incident radiation and the accelerating potential fixed, the intensity of light is varied, then
Answer : Option D
Explaination / Solution:
With increase in intensity no. of photon incident increases. So that more electron emitted from metal and photo current increases with increase in intensity.
Q2. An amendment in Air (Prevention and control of Pollution) Act1981 included a new pollutant named :
Answer : Option C
Explaination / Solution:
The Air (Prevention and Control of Pollution) Act, 1981 an Act of the Parliament of India to control and prevent air pollution in india. It was amended in 1987.
There are some definations of the act.
Definitions. – In this Act, unless the context otherwise requires,
- “air pollutant” means any solid, liquid or gaseous substance (including noise)] present in the atmosphere in such concentration as may be or tend to be injurious to human beings or other living creatures or plants or property or environment;
- “air pollution” means the presence in the atmosphere of any air pollutant;
- “approved appliance” means any equipment or gadget used for the burning of any combustible material or for generating or consuming any fume, gas or particulate matter and approved by the State Board for the purposes of this Act;
Q3. the centre of mass of a system of particles moves
Answer : Option B
Explaination / Solution:
The centre of mass of a system of particles moves as if all the mass of the system is concentrated at the centre and all the external forces were applied at that point. In order to ease the calculations involved in the dynamics of an extended body, we treat any extended body as the system of particles, and the motion of centre of mass of the system is calculated by taking the mass of the whole system to be concentrated at the centre of mass and the external forces acting on system are said to be acting on the centre of mass.
Q4. Fill up the blank with suitable word in the statement,
" Physical properties are those properties which are measured or observed--------------- changing the identity or the composition of the substance ."
Answer : Option D
Explaination / Solution:
A substance is identified by its composition , hence for measuring physical properties of a substance its identity must be retained , (or should not be changed ) Hence , the given statement ,
" Physical properties are those properties which are measured or observed without changing the identity or composition of the substance."
is correct.
Q5. For the same alkyl group, an alkyl bromide has a higher boiling point than alkyl fluoride because,
Answer : Option C
Explaination / Solution:
Vanderwall forces increases with increase in molecular mass and boiling point increases with vanderwall forces..
The main factor affecting the boiling point is the molecular weight, as can be pictured from the noble gases boiling point in the periodic table (the noble gases are those which have the weakest interactions due to their complete outer shell). But note that if you want to consider all the effects altogether, you must use Kelvins instead of Celsius. So going from 44°C to 88°C is not twice as much but a mere 14% increase.
The other factor affecting boiling point is the nature and strength of intermolecular interactions, usually in the order ionic > hydrogen bond > dipole-dipole > Van der Waals.
In the comparison of RF vs RBr boiling point, molecular weight is definitely in favor of higher boiling points for RBr, at least for small molecules. It is true that the C-F bond is much more ionized than C-Br so it will create stronger dipole-dipole interactions but not sufficiently to compensate for the effect of the mass increase.
Q6. A Mega =
Answer : Option A
Explaination / Solution:
No Explaination.
Q7. The number of asymmetric carbon atom(s) in below figure is are
Answer : Option A
Explaination / Solution:
Only 1 asymmetric center.
Q8. Transducer is a device that
Answer : Option B
Explaination / Solution:
Any device which converts energy from one form to another is called a transducer.It converts variation in physical quantities such as pressure,dispalcement,force,temprature etc.Like microphone converts sound signal into an electrical signal.
Q9. The living organism can be unexceptionally differ from non-living on the basis of
Answer : Option A
Explaination / Solution:
The living and non-living shows a number of different features including respiration, nutrition, growth and stimulus but reproduction is most distinctive feature to classify into living and non-living.
Q10. Consumption changes in the same direction as income. It is
Answer : Option A
Explaination / Solution:
No Explaination.
