The pressure of a given mass of a gas changes from 300Nm\(^{-2}\) to 120Nm\(^{-2}\) while the temperature drops from 127°C to -73°C. The ratio of the final volume to the initial volume is
- A. 2 : 5
- B. 5 : 4
- C. 4 : 5
- D. 5 : 2
The driving mirror of a car has a radius of curvature of 1m. A vehicle behind the car is 4m from the mirror. Find the image distance behind the mirror.
- A. 8/7
- B. 4/9
- C. 9/2
- D. 4/7
The terrestrial telescope has one extra lens more than the astronomical telescope. The extra lens is for
- A. improving the sharpness
- B. creating an inverted image
- C. magnification of the image
- D. erection of the image
A ray of light strikes a plane mirror at an angle of incidence of 35°. If the mirror is rotated through 10°, through what angle is the reflected ray rotated?
- A. 70°
- B. 45°
- C. 25°
- D. 20°
Ice cubes are added to a glass of warm water. The glass and water are cooled by
- A. conduction only
- B. convection only
- C. conduction and convection
- D. convection and radiation
Which of the following consists entirely of vector quantities?
- A. Velocity, displacement and reaction
- B. Tension, magnetic flux and mass
- C. Displacement, impulse and power
- D. Work, pressure and moment
The efficiency of a machine is always less than 100% because the
- A. work output is always greater than the work input
- B. load lifted is always greater than the effort applied
- C. effort applied is always greater than the load lifted
- D. velocity ratio is always greater than the mechanical advantage
I. The earth is not spherical but elliptical in shape
II. Variation in latitude and longitude
III. Rotation of the earth on its axis
IV. Variation in the density of the earth
On which combination of the above does the weight of an object vary on the earth’s surface?
- A. I, II, III and IV
- B. III and IV only
- C. I, II and III only
- D. I and II only
The resultant of two forces acting on an object is maximum if the angle between them is
- A. 45°
- B. 0°
- C. 90°
- D. 180°
If a spherical metal bob of radius 3cm is fully immersed in a cylinder containing water and the water level rises by 1cm, what is the radius of the cylinder?
- A. 12cm
- B. 1cm
- C. 3cm
- D. 6cm
A stone of mass 1kg is dropped from a height of 10m above the ground and falls freely under gravity. Its kinetic energy 5m above the ground is then equal to
- A. its kinetic energy on the ground
- B. twice its initial potential energy
- C. its initial potential energy
- D. half its initial potential energy
The height at which the atmosphere ceases to exist is about 80km. If the atmospheric pressure on the ground level is 760mmHg, the pressure at a height of 20km above the ground level is
- A. 380mmHg
- B. 570mmHg
- C. 190mmHg
- D. 480mmHg
Light of energy 5eV falls on a metal of work function 3eV and electrons are liberated. The stopping potential is
- A. 1.7V
- B. 2.0V
- C. 8.0V
- D. 15.0V
A conductor of length 2m carries a current of 0.8A while kept in a magnetic field of magnetic flux density 0.5T. The maximum force acting on it is
- A. 0.2N
- B. 0.8N
- C. 3.2N
- D. 8.0N
A cell of internal resistance 1Ω supplies current to an external resistor of 3Ω. The efficiency of the cell is
- A. 25%
- B. 33%
- C. 50%
- D. 75%
A 2H inductor has negligible resistance and is connected to a 50/π Hz A.C. Supply. The reactance of the inductor is
- A. 200 Ω
- B. 50 Ω
- C. 100/π Ω
- D. 25/π Ω
A certain radioactive source emits radiations that were found to be deflected by both magnetic and electric fields. The radiations are
- A. beta rays
- B. gamma rays
- C. x-rays
- D. ultra-violet rays
If the fraction of the atoms of a radioactive material left after 120years is 1/64, what is the half-life of the material?
- A. 24 years
- B. 20 years
- C. 10 years
- D. 2 years
If the frequency of an emitted x-ray is 1.6 x 10\(^{16}\)Hz, the accelerating potential is?
[e = 1.6 x 10\(^{19}\)C, h = 6.63 x 10\(^{-34}\)Js]
- A. 6630.0V
- B. 663.0V
- C. 66.3V
- D. 6.6V
An electric generator with a power output of 3.0KW at a voltage of 1.5KV distributes power along cables of resistance 20.0Ω. The power loss in the cables is
- A. 80.0W
- B. 40.0W
- C. 10.0W
- D. 0.1W
If ∆x is the uncertainty in the measurement of the position of a particle along the x-axis and ∆Pa is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as
- A. ∆x ∆Px ≥ h
- B. ∆x ∆Px = 0
- C. ∆x ∆Px < h
- D. ∆x ∆Px = ∞