An astronomical telescope is said to be in normal adjustment when the
- A. eye is accommodated
- B. focal length of objective 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 108ms-1 and 2.0 x 108ms-1 respectively. If the angle of refraction is 30°, 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 20cm
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 frequency of the wave motion.
- A. 0.25 x 10-3rad s-1
- B. 0.25 x 10-1rad s-1
- C. 5.00 x 102rad s-1
- D. 2.50 x 103rad s-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-1K-1
Latent heat of fusion of ice = 3.3 x 105JKg-1
- A. 8/33kg
- B. 33/80kg
- C. 80/33kg
- D. 33/8kg
The temperature gradient across a copper rod of thickness 0.02m, maintained at two temperature junctions of 20°C and 80°C respectively is
- A. 3.0 x 102Km-1
- B. 3.0 x 103Km-1
- C. 5.0 x 103Km-1
- D. 3.0 x 104Km-1
I. A liquid boils when its saturated vapour pressure is equal to the external pressure
II. Dissolved substances in pure water lead to increase in the boiling point.
III. When the external pressure is increased, the boiling point increases.
IV. Dissolved substances in pure water decrease the boiling point.
Which combination of the above are peculiarities of the boiling point of a liquid?
- A. I, II and III
- B. I, II, III and IV
- C. I, II and IV
- D. II, III and IV
A piece of substance of specific head capacity 450JKg-1K-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. 2/9°C
- B. 4/9°C
- C. 9/4°C
- D. 9/2°C
A gas at a volume of V0 in a container at pressure P0 is compressed to one-fifth of its volume. What will be its pressure if the magnitude of its original temperature T is constant?
- A. P0/5
- B. 4P0/5
- C. P0
- D. 5P0
When temperature of a liquid increases, its surface tension
- A. Decreases
- B. Increases
- C. Remain Constant
- D. Increases then decreases
A solid weigh 10 .00 N in air, 6 N when fully immersed in water and 7 . 0 N when fully immersed in a liquid X. Calculate the relative density of the liquid, X.
- A. 5/3
- B. 4/3
- C. 3/4
- D. 7/10
If the stress on a wire is 107NM-2 and the wire is stretched from its original length of 10.00 cm to 10.05 cm. The young’s modulus of the wire is
- A. 5 . 0 x 104 Nm-2
- B. 5 . 0 x 105 Nm-2
- C. 2 . 0 x 108 Nm-2
- D. 2 . 0 x 109 Nm-2
When the brakes in a car are applied, the frictional force force on the tyres is
- A. is a disadvantage because it is in the direction of the motion of the car
- B. is a disadvantage because it is in the opposite direction of the motion of the car
- C. is an advantage because it is in the direction of the motion of the car
- D. is 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 20 secs. The power developed in the engine is
- A. 1 . 25 x 104 W
- B. 2 . 50 x 104 W
- C. 1 . 25 x 106W
- D. 2 . 50 x 106 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. 5 J
- B. 10 J
- C. 15 J
- D. 20 J
A lead bullet of mass 0.05kg is fired with a velocity of 200ms\(^{-1}\) into a lead block of mass 0.95kg. Given that the lead block can move freely, the final kinetic energy after impact is
- A. 50 J
- B. 100 J
- C. 150 J
- D. 200 J
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. 2 N
- B. 20 N
- C. 200 N
- D. 400 N
Two bodies have masses in the ratio 3:1. They experience forces which impart to them acceleration in the ratio 2:9 respectively. Find the ratio of forces the masses experienced.
- A. 1 : 4
- B. 2 : 1
- C. 2 : 3
- D. 2 : 5