| 14 | N + | 4 | He → | 17 | O + X |
| 7 | 2 | 8 |
In the equation above, the particles X is?
- A. a proton
- B. a neutron
- C. an α - particle
- D. a β - particle
If electron are accelerated from rest through a potential difference of 10kv, what is the wavelength of the associated electron?
[m = 9.1 x 10\(^{-31}\)kg, e = 1.6 x 10\(^{-19}\)C, h = 6.6 x 10\(^{-34}\)js]
- A. 1.22 x 10-11m
- B. 3.87 x 10-10m
- C. 2.27 x 1011m
- D. 2.27 x 1014m
Given the inductor of inductance 5mH, 10mH and 20mH connected in series, the effective inductance is
- A. 0.35mH
- B. 3.50mH
- C. 2.90mH
- D. 35.0mH
Find the effective resistance in the diagram above
- A. 6 Ω
- B. 12 Ω
- C. 18 Ω
- D. 24 Ω
If a concave lens of focal length 12cm is used to produce a real image four times the size of the object, how far from the lens must the object be placed?
- A. 10 cm
- B. 15 cm
- C. 20 cm
- D. 25 cm
The above figure shows the motion of a progressive wave along a string. The particle motion of the medium is in direction?
- A. parallel to OX
- B. parallel to OY
- C. 60o to OX
- D. 60v to OY
The diagram above is the heating curve for a solid, QR is the?
- A. melting region
- B. boiling region
- C. sublimation region
- D. evaporating process
The efficiency of the pulley system shown above is 80%. find the effort E required to lift the load of 1200N
- A. 275N
- B. 325N
- C. 375N
- D. 573N
The diagram above shows a plank RS pivoted its center of gravity O and is in equilibrium with the weight P and Q. If a weight 2P is added to P the plank will be in equilibrium again by?
- A. moving Q nearer to O
- B. moving P nearer to O
- C. addding a weight Q to Q
- D. moving P further away from O
A body of mass 4 kg resting on a smooth horizontal plane is simultaneously acted upon by two perpendicular forces 6N and 8N. Calculate the acceleration of the motion
- A. 2.5 ms-1
- B. 3.0 ms-1
- C. 4.0 ms-1
- D. 4.5 ms-1
A force F required to keep a 5 kg mass moving round a cycle of radius 3.5 m at a speed of 7 ms-1. What is the speed, if the force is tripled?
- A. 4.0 ms-1
- B. 6.6 ms-1
- C. 12.1 ms-1
- D. 21.0 ms-1
The resultant of two forces 12N and 5N is 13N. What is the angle between the two forces?
- A. 0o
- B. 45o
- C. 90o
- D. 180o
The dimension of electromotive force are?
- A. ML2T-3I-1
- B. ML2T-3I-2
- C. M2LT-2I-1
- D. M2L2T-1I-1
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