Physics - Online Test
Q1.
Two billiard balls each of mass 0.05 kg moving in opposite directions with speed 6 m collide and rebound with the same speed. What is the impulse imparted to each ball due to the other?
Answer : Option D
Explaination / Solution:
Impulse imparted to one ball by the other = change in momentum
= momentum after collision - momentum before collision
= {0.05 x 6} - {0.05x(-6)}
= 0.6 kg m s-1
Q2. A 75.0-kg painter climbs a ladder that is 2.75 m long leaning against a vertical wall. The ladder makes an angle of angle with the wall. How much work does gravity do on the painter?
Answer : Option B
Explaination / Solution:
W=−mghh=xcos30∘=2.75×3–√2W=−75×9.8×2.75×3–√2=−1750J
Q3. The resistance of a metallic conductor increases due to
Answer : Option C
Explaination / Solution:
Resistance of a metal of length l , area A is where n is the carrier density, m the mass of the electron , e the charge of the electron and , the average time between two collisions. at constant temperature, n and remain constant. is constant at constant temperature and is called The resistance increases if the length increases or the area decreases.
Q4. A beam of alpha particles is incident on a target of lead. A particular alpha particle comes in “head-on” to a particular lead nucleus and stops 6.5 m away from the center of the nucleus. (This point is well outside the nucleus.) Assume that the lead nucleus, which has 82 protons, remains at rest. The mass of the alpha particle is 6.64 kg . Calculate the electrostatic potential energy at the instant that the alpha particle stops. Express your result in MeV.
Answer : Option B
Explaination / Solution:
No Explaination.
Q5. A parallel plate capacitor of capacitance C is connected to a battery and is charged to a potential difference V. Another capacitor of capacitance 2C is similarly charged to a potential difference 2V. The charging battery is then disconnected and the capacitors are connected in parallel to each other in such a way that the positive terminal of one is connected to the negative terminal of the other. The final energy of the configuration is
Answer : Option D
Explaination / Solution:
The charges Q1 and Q2 on the two capacitors .The capacitors are connected in parallel in such a way that the positive plate of one is connected to the negative plate of the other. The common potential.The final energy
Q6. A thin uniform rod of length 2l and mass M is acted upon a constant torque. The angular velocity changes from zero to ωω in time t. The value of torque is
Answer : Option B
Explaination / Solution:
As Torque() is equal to product of Moment of Inertia (I) and Angular acceleration
Q7. What will be the height of a liquid column in a capillary tube on the surface of the moon?
Answer : Option B
Explaination / Solution:
No Explaination.
Q8. in every conservation principle
Answer : Option C
Explaination / Solution:
In physics, a conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves over time. Exact conservation laws include conservation of energy, conservation of linear momentum, conservation of angular momentum, and conservation of electric charge.
Q9. One mole of hydrogen gas is heated at constant pressure from 300 K to 420 K. Calculate the work done by the gas.
Answer : Option D
Explaination / Solution:
In isobaric process
Q10. An object and a screen are mounted on an optical bench and a converging lens is placed between them so that a sharp image is received on the screen. The linear magnification of the image is 2.5. The lens is now moved 30 cm nearer the screen and a sharp image is again formed on the screen. The focal length of the lens is
Answer : Option C
Explaination / Solution:
No Explaination.
