Physics - Online Test
Q1. An electron moves straight
inside a charged parallel plate capacitor of uniform charge density σ. The time
taken by the electron to cross the parallel plate capacitor when the plates of
the capacitor are kept under constant magnetic field of induction 
is
is
Answer : Option D
Explaination / Solution:
Q2. Doping a semiconductor results in
Answer : Option C
Explaination / Solution:
No Explaination.
Q3. Vectors can be added by
Answer : Option A
Explaination / Solution:
The sum of two or more vectors is called the resultant. The resultant of two vectors can be found using either the triangle method or the parallelogram method.
Q4. Identify the unit vector in the following.
Answer : Option D
Explaination / Solution:
No Explaination.
Q5. Thermodynamics is the branch of physics that deals with.
Answer : Option B
Explaination / Solution:
Thermodynamics is a branch of physics concerned with heat and temperature and their relation to energy and work. It deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy), and, by extension, of the relationships between all forms of energy.
Q6.
A thin semi-circular conducting ring (PQR) of radius r is falling
with its plane vertical in a horizontal magnetic field B, as shown in the
figure.
Answer : Option D
Explaination / Solution:
Q7. If electrons move out of a body to another body every second, how much time is approximately required to get a total charge of 1 C on the other body?
Answer : Option A
Explaination / Solution:
We know that 1 Coulomb = 6.242×1018 eletrons
given 109 electrons take 1 secs
=> 109 electrons ------> 1 sec
=> 1 electrons ---------> secs
=> 6.242×1018 ------>
= 6.242×109 secs = years
=197.93 years= 200 years approx
Q8. Elasticity is the property of a body, by virtue of which
Answer : Option C
Explaination / Solution:
When external force is applied on the solid bodies, the solid bodies get deformed. The atoms or molecules are displaced from their equilibrium positions causing a change in the interatomic ( or intermolicular ) distances. When the deforming foce is removed, the interatomic forces tend to drive them back to their original postions. Thus the body regains its original shape and size.
Q9. An object of mass m held against a vertical wall by applying horizontal
force F as shown in the figure. The minimum value of the force F is
Answer : Option C
Explaination / Solution:
No Explaination.
Q10. Which one of the following is the natural nanomaterial.
Answer : Option A
Explaination / Solution:
No Explaination.
