Physics - Online Test
Q1. Physics is a
Answer : Option C
Explaination / Solution:
The natural sciences seek to understand how the world and universe around us works. There are five major branches (top left to bottom right): Chemistry, astronomy, earth science, physics, and biology.
Q2. The scalar product of two vectors A and B is
Answer : Option C
Explaination / Solution:
Scalar product means dot product and dot product of 2 vectors gives a scalar , example dot product of force and displacement gives work which is scalar
Q3. Electronic communication refers to
Answer : Option B
Explaination / Solution:
When information are sent from one point to the other it has to be converted into electrical signal using transducer.The receiver receives it in its original from using receiver.Such from of communication is called electronic communication.
Q4. The basic difference between a scalar and vector is one of
Answer : Option B
Explaination / Solution:
Scalar quantity gives you an idea about how much of an object there is, but vector quantity gives you an indication of how much of an object there is and that also in which direction. So, the main difference between these two quantities is associated with the direction, i.e. scalars do not have direction but vectors do.
Q5. The picture of heat as a fluid was discarded in favor of the modern concept of heat as a form of energy because
Answer : Option C
Explaination / Solution:
If heat were actually a substance, as many scientists of the time believed, it was difficult to see how so much of it could be produced during the boring of a metal cannon. Rumford showed that the amount of heat was not related to the quantity of filings produced
Q6. Which of the following methods can be used to charge a metal sphere positively without touching it . Select the best
Answer : Option C
Explaination / Solution:
This can be possible by induction, if a negative charge rod is placed near the sphere (at a distance not in touch) than it attracts positive charge inside the sphere towards its side and the negative charges collected on other side and when the surface of sphere connected to earth than the negative charge goes to earth and the sphere remain positively charged.
Q7. A perfectly rigid body is one
Answer : Option A
Explaination / Solution:
A perfectly rigid body is hypothetical in nature but for some phenomena ( in rotational bodies ) we assume bodies are perfectly rigid i.e. the intermolecular forces are always in equilibrium irrespective of the external forces due to which their shape and size are constant.
Q8. According to ‘plum pudding model’ atoms on the whole are electrically neutral because
Answer : Option C
Explaination / Solution:
No Explaination.
Q9. force is required
Answer : Option D
Explaination / Solution:
force is required to start a stationary object and to stop a moving object due to inertia. Inertia is a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force. This is also called law of inertia or newton's first law of motion
Q10. Domestic power supply in India is
Answer : Option B
Explaination / Solution:
The standard voltage and frequency of alternating current supply in India is set to 220 V and 50Hz respectively by the government of India because
when power has to be transmitted from a power plant, the biggest challenge is to cut the transmission losses. For this purpose, the current value should be small and potential difference(Voltage) should be more. Also losses are minimal at 50 Hz/60 Hz frequency.
