Physics - Online Test
Q1. Vectors can be added by
Answer : Option B
Explaination / Solution:
Vector addition is the operation of adding two or more vectors together into a vector sum. The so-called parallelogram law gives the rule for vector addition of two or more vectors. For two vectors, the vector sum is obtained by placing them head to tail and drawing the vector from the free tail to the free head.
Q2. A point charge + q is placed at the mid point of a cube of side L. The electric flux emerging from the cube is
Answer : Option B
Explaination / Solution:
Since the charge inside cube is q so by Gauss theorem the total flux through the cube is
Q3.
Compute the fractional change in volume of a glass slab, when subjected to a hydraulic pressure of 10 atm. Bulk modulus of glass 37 GPa.
Answer : Option B
Explaination / Solution:
No Explaination.
Q4.
Consider the cyclic process depicted in Figure If Q is negative for the process BC, and if is negative for the process CA, what are the signs of Q, W, and that are associated with AB?
Answer : Option C
Explaination / Solution:
W = +ve (Expansion)
Q5. If the charge on a capacitor is increased by 2 coulomb, the energy stored in it increases by 21%. The original charge on the capacitor (in coulomb) is
Answer : Option B
Explaination / Solution:
The initial energy of the capacitor of capacitance C and charge Q1 is .When the charge increases to Q2 the energy of the capacitor Given percentage increase of energy
. But Solving
. But Solving
Q6. One mole of an ideal monatomic gas is at an initial temperature of 300 K. The gas undergoes an isovolumetric process, acquiring 500 J of energy by heat. It then undergoes an isobaric process, losing this same amount of energy by heat. Determine the new temperature of the gas
Answer : Option A
Explaination / Solution:
for monoatomic gas CV = 1.5R, CP = 2.5R
At const volume,
Q = 500 J
At const pressure Q = 500 J
Q7. The displacement of a particle executing S.H.M is given by y=0.25 sin 200 t cm. The maximum speed of the particle is
Answer : Option D
Explaination / Solution:
No Explaination.
Q8. A closely wound solenoid of 2000 turns and area of cross-section , carrying a current of 4.0 A, is suspended through its centre allowing it to turn in a horizontal plane. If a uniform horizontal magnetic field of T is set up at an angle of with the axis of the solenoid,force and torque on the solenoid are
Answer : Option A
Explaination / Solution:
No Explaination.
Q9. A particle of mass m and charge q is released from rest in a uniform electric field E. The kinetic energy attained by the particle after moving a distance x is
Answer : Option A
Explaination / Solution:
If a charge q moving in electric field F=qE, displacement=x W=Force X displacement W=qE x=Kinetic energy
Q10. A parallel plate capacitor of capacity 100 μF is charged by a battery of 50 volts. The battery remains connected and if the plates of the capacitor are brought closer so that the distance between them becomes half the original distance, the additional energy given by the battery to the capacitor in joules is:
Answer : Option C
Explaination / Solution:
Initial energy of the capacitor. When the plates are kept at half the original distance, the new capacitance
Final energy Increase in energy = additional energy given by the battery=
Final energy Increase in energy = additional energy given by the battery=
