If a cage containing a truck of coal weighing 750 kg is raised to a height of 90 m in a minute, what is the total power expended?
[g = 10 ms2]
- A. 11.50 kw
- B. 12.60 kw
- C. 11.25 kw
- D. 12.10 kw
I. The motion of the tyres of a moving car.
II. The motion of a loaded test tube oscillated
vertically.
III. The beating of the heart.
IV. A stone tied to a string and whirled round.
V. The motion of the pistons in a gasoline engine.
Which of the motions above is simple harmonic?
- A. III, IV and V only
- B. II, III and V only
- C. II, III and IV only
- D. I,II and III only
A bullet fired vertically upward from a gun held 2.0 m above the ground reaches its maximum height in 4.0s. calculate its initial velocity.
[g = 10ms-2]
- A. 10 ms-1
- B. 8 ms-1
- C. 40 ms-1
- D. 20 ms-1
What is the acceleration between two points on a velocity time graph which has coordinates
(10s, 15 ms-1)
and (20 s, 35 ms-1)?
- A. 1.7 ms-2
- B. 3.50 ms-2
- C. 1.00 ms-2
- D. 2.00 ms-2
I. Diameter of a small ball bearing.
II. Thickness of a pieces of paper.
III. Diameter of a measuring cylinder.
IV. Length of a piece of wire.
Which of the above can be measured using a micrometer screw gauge?
- A. I, II and IV only .
- B. I and II only
- C. II and III only
- D. III and IV only
I. for current amplification.
II. for voltage stabilization.
III. for power amplification.
IV. as a switch.
which of the above are the uses of transistor?
- A. I,II,III and IV
- B. I,III, and IV only
- C. I, II and III only
- D. I,II and IV only
When a pure semiconductor is heated, its resistance?
- A. increases
- B. decreases
- C. remains the same
- D. increases and then decreases
zener diode is used for?
- A. current amplification
- B. power amplification
- C. voltage regulation
- D. energy conversion
caesium has a work function of 3 x 10-19J. the maximum energy of liberated electrons when it is illuminated by light of frequency 6.7 x 1014
HZ is?
[h = 6.6 x 1010-34Js]
- A. 1.42 x 10-19J
- B. 3.00 x 10-19J
- C. 4.42 x 1010-19J
- D. 7.42 x 10-19J
A step-down transformer has a power output of 50 W and efficiency of 80%. if the mains supply voltage is 200 v, calculate the primary current of the transformer.
- A. 0.31 A
- B. 3.20 A
- C. 3.40 A
- D. 5.00 A
The d.c generator has essentially the same components as the a.c generator except the presence of?
- A. slip-ring
- B. carbon brushes
- C. split ring
- D. armature
A generator is on daily use and in the process, ten 60 W and five 40 W tungsten bulbs are on for the same time interval. the energy consumed daily is?
- A. 0.96 kWh
- B. 1.92 kWh
- C. 9.60 kWh
- D. 19.20 kWh
An electric generator has e.m.f. of 240 V and an internal resistance of 1Ω if the current supplied by the generator is 20A when the terminal voltage is 220 V, find the ratio of the power supplied to the power dissipated?
- A. 11:1
- B. 1:11
- C. 12:11
- D. 11:12
A short chain is sometimes attached to the back of a petrol tanker to?
- A. generate more friction
- B. ensure the balancing of the tanker
- C. caution the driver when overspeeding
- D. conduct excess charges to the earth
Short sightedness can be corrected by what type of lens?
- A. Concave lens
- B. Convex lens
- C. Converging lens
- D. Mirrors
In the microscope, the eyepiece lens merely acts as?
- A. an inverter
- B. a refiner
- C. a diminisher
- D. a magnifier
An object placed at the bottom of a well full of clear water appears closer to the surface due to?
- A. diffraction
- B. reflection
- C. refraction
- D. polarization
Convex mirror are used as driving mirrors because images formed are?
- A. erect, virtual and diminished
- B. erect, real and diminished
- C. erect, virtual and magnified
- D. inverted virtual and diminished
An object of heights 5 cm is placed at 20 cm from a concave mirror of focal length 10 cm. the image height is?
- A. 20 cm
- B. 15 cm
- C. 10 cm
- D. 5 cm
An object of height 4cm is placed in front of a cuboid pinhole camera of size 6 cm. if the image formed is 2 cm high, how far is the object from the pinhole?
- A. 3.0 cm
- B. 8.0 cm
- C. 12.0 cm
- D. 16.0 cm
I. Total internal reflection of light.
II. Conservation of light energy.
III. Relative motion of the earth, sun and moon.
IV. Rectilinear propagation of light.
which of the above is a phenomenon of total solar eclipse?
- A. I and IV only
- B. II and IV only
- C. I and III only
- D. III and IV only