A 2H inductor has negligible resistance and is connected to a \(\frac{50}{\pi}\) Hz A.C supply. The reactance of the inductor is?
- A. 200\(\Omega\)
- B. 50\(\Omega\)
- C. \(\frac{100}{\pi}\)
- D. \(\frac{25}{\pi \Omega}\)
An astronomical telescope is said to be in normal adjustment when the?
- A. eye is accommodated
- B. focal length of an object lens is longer than that of eye piece
- C. final image is at the near point of eye
- D. final image is at infinity
The velocities of light in air and glass are 3.0 x 10\(^8\)ms\(^{-1}\) and 2.0 x 10\(^8\)ms\(^{-1}\) respectively. If the angle of refraction is 30º, the sine of the angle of incidence is?
- A. 0.33
- B. 0.50
- C. 0.67
- D. 0.75
The inside portion of part of a hollow metal sphere of diameter 20cm is polished. The portion will therefore form a?
- A. concave mirror of focal length 5cm
- B. concave mirror of focal length 10cm
- C. convex mirror of focal length 5cm
- D. convex mirror of focal length 10cm
A man stands 4m in front of a plane mirror. If the mirror is moved 1m towards the man, the distance between him and his new image is?
- A. 3m
- B. 5m
- C. 6m
- D. 10m
The lowest note emitted by a stretched string has a frequency of 40Hz. How many overtones are there between 40Hz and 180Hz?
- A. 4
- B. 3
- C. 2
- D. 1
If a sound wave goes from a cold air region to a hot air region, its wavelength will?
- A. increase
- B. decrease
- C. decrease then increase
- D. remain constant
The equation of a wave traveling along the positive x-direction is given by; y = 0.25 x 10\(^{-3}\) sin (500t – 0.025x). Determine the angular velocity of the wave motion.
- A. 0.25 x 10\(^{-3}\)rads\(^{-1}\)
- B. 0.25 x 10\(^{-1}\)rads\(^{-1}\)
- C. 5.00 x 10\(^{2}\)rads\(^{-1}\)
- D. 2.50 x 10\(^{3}\)rads\(^{-1}\)
Calculate the mass of ice that would melt when 2kg of copper is quickly transferred from boiling water to a block of ice without heat loss (specific heat capacity of copper = 400Jkg\(^{1}\)k\(^{-1}\), latent heat of fusion of ice = 3.3 x 10\(^{5}\)Jkg\(^{-1}\))
- A. \(\frac{8}{33}\)kg
- B. \(\frac{3.3}{80}\)kg
- C. \(\frac{80}{33}\)kg
- D. \(\frac{3.3}{8}\)kg
The temperature gradient across a copper rod of thickness 0.02m, maintained at two temperature junctions of 20º and 80ºC respectively is?
- A. 3.0 x 10\(^{2}\)km\(^{-1}\)
- B. 3.0 x 10\(^{3}\)km\(^{-1}\)
- C. 5.0 x 10\(^{3}\)km\(^{-1}\)
- D. 3.0 x 10\(^{4}\)km\(^{-1}\)
I. A liquid boils when its saturated vapor pressure is equal to the external pressure
II. Dissolved substances in pure water lead to an increase in the boiling point.
III. When the external pressure is increased, the boiling point increases.
IV. Dissolved substances in pure water decreases the boiling point
Which of the above combinations are peculiarities of the boiling point of a liquid?
- A. I, II and III only
- B. I, II, III, and IV
- C. I, II, and IV
- D. II, III, and IV
A piece of substance of specific heat capacity 450Jkg\(^{-1}\)k\(^{1}\) falls through a vertical distance of 20m from rest. Calculate the rise in temperature of the substance on hitting the ground when all its energies are converted into heat. [g = 10ms\(^{-2}\)]
- A. \(\frac{2}{9}\)ºC
- B. \(\frac{4}{9}\)ºC
- C. \(\frac{9}{2}\)ºC
- D. \(\frac{9}{4}\)ºC
A gas at a volume of V\(_{0}\) in a container at pressure p\(_{0}\) is compressed to one-fifth of its volume. What will be its pressure if the magnitude of its original temperature T is constant?
- A. \(\frac{p_{0}} {5}\)
- B. \(\frac{4p_{0}}{5}\)
- C. p\(_{0}\)
- D. 5P\(_{0}\)
When the temperature of a liquid increases, its surface tension
- A. decreases
- B. increases
- C. remains constant
- D. increases then decreases
A solid weighs 10.00N in air, 6N when forcefully immersed in water, and 7.0N when fully immersed in a liquid, X. Calculate the relative density of the liquid X.
- A. \(\frac{5}{3}\)
- B. \(\frac{4}{3}\)
- C. \(\frac{3}{4}\)
- D. \(\frac{7}{10}\)
If the stress on a wire is 10\(^{7}\)NM\(^{-2}\) and the wire is stretched from its original length of 10.00m to 10.05m. The young’s modulus of the wire is?
- A. 5.0 x 10\(^{-4}\)Nm\(^{-2}\)
- B. 5.0 x 10\(^{-5}\)Nm\(^{-2}\)
- C. 2.0 x 10\(^{-8}\)Nm\(^{-2}\)
- D. 2.0 x 10\(^{9}\)Nm\(^{-2}\)
When the breaks in a car are applied, the frictional force on the tyres is?
- A. a disadvantage because it is in the direction of the motion of the car
- B. a disadvantage because it is in the opposite direction of the motion of the car
- C. an advantage because it is in the direction of the motion of the car
- D. an advantage because it is in the opposite direction of the motion of the car
A car of mass 800kg attains a speed of 25m/s in 20secs. The power developed in the engine is?
- A. 1.25 x 10\(^{4}\)W
- B. 2.50x 10\(^{4}\)W
- C. 1.25 x 10\(^{6}\)W
- D. 2.50 x 10\(^{6}\)W
A ball of mass 0.1kg is thrown vertically upwards with a speed of 10ms\(^{-1}\) from the top of a tower 10m high. Neglecting air resistance, its total energy just before hitting the ground is? (Take g = 10ms\(^{-2}\))
- A. 5J
- B. 10J
- C. 15J
- D. 20J
A lead bullet of mass 0.05kg is fired with a velocity of 200ms\(^{-1}\) into a block of mass 0.95kg. Given that the lead block can move freely, the final kinetic energy after impact is?
- A. 50J
- B. 100J
- C. 150J
- D. 200J
Particles of mass 10\(^{-2}\)kg is fixed to the tip of a fan blade which rotates with angular velocity of 100rad\(^{-1}\). If the radius of the blade is 0.2m, the centripetal force is?
- A. 2N
- B. 20N
- C. 200N
- D. 400N