Physics - Online Test
Q1. An AC generator consists of
Answer : Option D
Explaination / Solution:
AC generators operate on the same fundamental principles of electromagnetic induction.The turning of a coil in a magnetic field produces motional emfs in both sides of the coil.
A slip ring is a method of making an electrical connection through a rotating assembly. Formally, it is an electric transmission device that allows energy flow between two electrical rotating parts, such as in a motor.
Q2. A photoelectric cell converts
Answer : Option B
Explaination / Solution:
No Explaination.
Q3. Range of an electronic communication system
Answer : Option C
Explaination / Solution:
As the distance between the source and the destination increases the strenght of the transmitted signals become weaker and weaker and the distance where it loses energy to travel any more is range of the signal.
Q4. Which of the following physical quantities a scalar?
Answer : Option D
Explaination / Solution:
Work is defined as a dot-product (or scalar product) of force and displacement, both of which are vectors.
A scalar (dot) product of two vectors gives a scalar result.
Q5. Which of the following laws used to solve problems in collisions?
Answer : Option B
Explaination / Solution:
If external force is absent then linear momentum of system remains conserved. In collision force of impact due to collision is internal and very large.
Q6. Electric flux
Answer : Option A
Explaination / Solution:
Flux—It means flow Electric Flux—The number of electric field lines passing through any area normally known as electric flux. It is given by ϕ=E × area flux is a scalar quantity
Q7. For a rope of yield strength loaded in tension with weight Mg the minimum area A of the rope should be
Answer : Option B
Explaination / Solution:
We know that Yield strength times the Area give the weight of the body.
As Yield strength = weight of body/area
For safety purposes
Yield strength weight of body/area
Mg/A
A Mg/
Q8. The coefficient of performance K of a refrigerator is given by
Answer : Option D
Explaination / Solution:
The performance of refrigerator is expressed by means of cofficient of performance
cofficient of performance = Heat extracted / work done =
Q9. Reason why there are many lines in an atomic spectrum is because
Answer : Option A
Explaination / Solution:
No Explaination.
Q10. In which of the following cases is the net force non zero?
Answer : Option B
Explaination / Solution:
The force acting on a coin is due to gravitational force which causes an acceleration in downward direction.
