Physics - Online Test
Q1. A thermodynamic system is taken from an original state to an intermediate state by the linear process shown in Figure. Its volume is then reduced to the original value from E to F by an isobaric process. Calculate the total work done by the gas from D to E to F
Answer : Option B
Explaination / Solution:
work done by the gas is equal to area under P-V curve
Q2. Using the Bohr’s model calculate the speed of the electron in a hydrogen atom in the n = 1, 2, and 3 levels.
Answer : Option D
Explaination / Solution:
No Explaination.
Q3. A bob of mass 0.1 kg hung from the ceiling of a room by a string 2 m long is set into oscillation. The speed of the bob at its mean position is 1 m .What is the trajectory of the bob if the string is cut when the bob is at its mean position?
Answer : Option B
Explaination / Solution:
At the mean position, the bob has a horizontal velocity. so when the string is cut, it will fall along a parabolic path under the effect of gravity.
Q4. Consider the collision of two cars. Car 1 is at rest and Car 2 is moving at a speed of 2 m /s in the negative x-direction. Both cars each have a mass of 500 kg. The cars collide inelastically and stick together. What is the resulting velocity of the resulting mass of metal?
Answer : Option B
Explaination / Solution:
from conservation of linear momentum initial momentum = final momentum
negative sign indicate that cars moves to the left.
Q5. Fundamental forces in nature are those
Answer : Option A
Explaination / Solution:
The universe has a lot of forces, a lot of pushes and pulls. We're always pushing or pulling something, even if only the ground. But it turns out that in physics, there are really only four fundamental forces from which everything else is derived: the strong force, the weak force, the electromagnetic force, and the gravitational force.
Q6. An electrolytic capacitor is marked 8 μF, 220 V. It can be used in a circuit where the p.d. across the capacitor may be
Answer : Option D
Explaination / Solution:
The break down potential of the capacitor is 220 V. In order to prevent damage to a capacitor, it should be always used in a circuit where the p.d is less than its break down potential. The p.d difference can only be 200 V.
Q7. A fly wheel rotating about a fixed axis has a kinetic energy of 360 joule when its angular speed is 30 radians per second. The moment of inertia of the fly wheel about the axis of rotation is
Answer : Option B
Explaination / Solution:
K=12Iω2K=360Jω=30rad/sI=2Kω2=2×36030×30=0.8Kgm2
Q8. When a soap bubble is charged, it
Answer : Option B
Explaination / Solution:
Charge will be distributed uniformly on the surface of a bubble if the bubble is charged.The bubble will expand because the charged particles uniformly distributed on it cause them to repel each other due to the electrostatic force. This will happen to both positive and negatively charged bubbles because of the charge on it.
Q9. In a 30.0-s interval, 500 hailstones strike a glass window with an area of 0.600 at an angle of 45.0 to the window surface. Each hailstone has a mass of 5.00 g and a speed of 8.00 m/s. If the collisions are elastic, what are the average force and pressure on the window?
Answer : Option B
Explaination / Solution:
Q10. Spherical aberration in a thin lens can be reduced by
Answer : Option B
Explaination / Solution:
No Explaination.
