Physics - Online Test
Q1. For measuring μA current the galvanometer is
Answer : Option C
Explaination / Solution:
For measurement of current of any magnitude, the galvanometer is always connected in series. This is to ensure that the entire current flows through the galvanometer. If the galvanometer were connected in parallel, the current branches out and only a part of the current will flow through it.
Q2. If an equation is dimensionally consistent
Answer : Option C
Explaination / Solution:
Principle of homogenity of dimensions states that “For an equation to be dimansionally correct, the dimensions of each term on LHS must be equal to the dimensions of each term on RHS.”
Q3. A Wheatstone bridge ABCD is balanced with a galvanometer between the points B and D. At balance the resistance between the points B and D is :
Answer : Option D
Explaination / Solution:
No current passes through the Galvanometer in the bridge balance condition.
Therefore, the resistance between B and D is infinite.
Q4. What is constant in simple harmonic motion?
Answer : Option B
Explaination / Solution:
The time period of the SHM is given by where 'm' be the mass of the body (constant) , 'k' restoring force constant as T depends on 'm' and 'k' and they are constant for the system, so the corresponding Time period of the motion is Constant.
Q5. In the single slit diffraction, every point on the slit acts-
Answer : Option A
Explaination / Solution:
Every part of the wavefront at the slit acts as secondary sources because the incoming wavefront is parallel to the plane of the slit, these sources are in phase.
Q6. permanent magnets should have
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. Polar satellites
Answer : Option B
Explaination / Solution:
A polar orbiting satellite closely parallels the earth's meridian lines. It passes over the north and south poles each revolution. As the earth rotates to the east beneath the satellite, each pass monitors an area to the west of the previous pass at intervals of roughly 90 to 100 minutes. These strips can be pieced together to produce a picture of a larger area.They are used in monitoring the weather, observing the Earth’s surface, military uses including spying.
Q8. In an insulator, the forbidden energy gap between the valance band and conduction band is of the order of
Answer : Option B
Explaination / Solution:
In an insulator, the forbidden energy gap is very large.In general, the forbidden energy gap is more than 5eV and almost no electrons are available for conduction. Therefore, a very large amount of energy must be supplied to a valence electron to enable it to move to the conduction band.
In the case of materials like glass, the valence band is completely filled at 0 K. The energy gap between valence band and conduction band is of the order of 10 eV. Even in the presence of high electric field, the electrons cannot move from valence band to conduction band.
Q9.
A car is traveling due west at 20.0 m/s. Find the velocity of the car after 37.00 s if its constant acceleration is 1.0 m/s2 due east. Assume the acceleration remains constant.
Answer : Option A
Explaination / Solution:
Let's let west direction as +ve.
Initial velocity u = + 20.0 m/s
Final velocity = ?
Acceleration a = - 1.0 m/s2
Time taken t = 37.0 s
We know,
v = u + at
=>
=> v = -17.0
-ve sign shows direction of velocity is opposite. So velocity is 17.0 m/s due east.
Q10. A travelling wave, at a rigid boundary or a closed end,
Answer : Option B
Explaination / Solution:
No Explaination.
