Physics Past Questions And Answers
In an elastic collision
I. Energy is conserved II. Energy is decreased III. Energy is increased IV. Linear momentum conserved
- A. I only
- B. I and IV only
- C. II only
- D. III only
In the day time, it is possible to see under shady areas such as under a tree because light has undergone
- A. internal reflection
- B. refraction
- C. diffraction
- D. diffuse reflection
The sharpness of the boundary of the shadow of an object is determined by the
- A. intensity of light striking the object
- B. rays of light passing through the object
- C. nature of the object
- D. opacity of the object
A machine is said to be a third class lever when the
- A. load is between the fulcrum and effort
- B. fulcrum is between the effort and the load
- C. effort is between the fulcrum and load
- D. fulcrum is directly below the load
Which of the following relations about the focal length fo of the objective and focal length fe of the eye piece of a compound is correct?
- A. fo = fe
- B. fo < fe
- C. fo > fe
- D. fe = 2fo
How can energy loss be minimized through Eddy-current?
- A. By using high resistance wire
- B. By using insulated soft iron wires
- C. By using low resistance wires
- D. By using turns of wires
A sonometer wire is vibrating at frequency fo. If the tension in the wire is doubted while the length and the mass per unit length are kept constant, the new frequency of vibration is
- A. fo/2
- B. 2fo
- C. fo/√2
- D. fo√2
A body of mass 120g placed at the 10cm mark on a uniform metre rule makes the rule settle horizontally on a fulcrum places at 35cm mark. Calculate the mass of the rule
- A. 60g
- B. 80g
- C. 120g
- D. 200g
Cancerous cells can be destroyed by
- A) ultraviolet rays
- B) alpha particles
- C) x - rays
- D) infrared rays
A uniform rod PQ of length 1m and mass 2kg is pivoted at the end p. If load of 14N is placed at the center of the rod, find the force that should be applied vertically upwards at Q to maintain the rod at equilibrium horizontally [g = 10ms-2]
- A. 68N
- B. 28N
- C. 17N
- D. 7N

