Physics - Online Test
Q1.
Consider the situation shown in the figure. The capacitor A has a charge q on it whereas B is uncharged. The charge appearing on the capacitor B a long time after the switch is closed is
Answer : Option D
Explaination / Solution:
the charge –q is bound to the charge +q. Therefore no charge will appear on the capacitor B. The capacitor B will acquire a charge only if a battery ( driving force) is put in the circuit.
Q2.
Three thin uniform rods each of mass M and length L are placed along the three axis of a Cartesian coordinate system with one end of each rod at the origin. The M.I. of the system about z- axis is
Answer : Option B
Explaination / Solution:
Moment of inertia about an axis passing through edge
Moment of inertia of system about z-axis
Q3. Soldering of two metals possible because of the property of
Answer : Option D
Explaination / Solution:
No Explaination.
Q4. The law of conservation of energy is.
Answer : Option B
Explaination / Solution:
The law of conservation of energy is thought to be valid across all domains of nature, from the microscopic to the macroscopic. It is routinely applied in the analysis of atomic, nuclear and elementary particle processes. At the other end. all kinds of violent phenomena occur in the universe all the time. Yet the total energy of the universe (the most ideal isolated system possible!) is believed to remain unchanged.
Q5. 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
Q6. A convex lens forms a real image of an object on a screen; the magnification of the image being 3/2. The object and the screen are kept fixed and the lens is moved through a distance of 16 cm when a sharp image is again formed on the screen; the magnification now being 2/3. What is the focal length of the lens?
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. A radio-active element has half life of 15 yrs. What is the fraction that will decay in 30 yrs?.
Answer : Option B
Explaination / Solution:
No Explaination.
Q8. In an insulated vessel, 250 g of ice at 0C is added to 600 g of water at 18.0C. How much ice remains when the system reaches equilibrium?
Answer : Option C
Explaination / Solution:
No Explaination.
Q9. Horse power is unit of
Answer : Option B
Explaination / Solution:
The horsepower (hp) is a unit in the foot-pound-second ( fps ) or English system, sometimes used to express the rate at which mechanical energy is expended. It was originally defined as 550 foot-pounds per second (ft-lb/s). A power level of 1 hp is approximately equivalent to 746 watt.
Q10. A weightless spring which has a force constant k oscillates with frequency n when a mass m is suspended from it. The spring is cut into two equal halves and a mass 2m is suspended from it. The frequency of oscillation will now become
Answer : Option D
Explaination / Solution:
No Explaination.
