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
118.8cm2 surface of the copper cathode of a voltameter is to be coated with 10-6m thick copper of density 9 x 103kgm-3. How long will the process run with 10A constant current?
[3.3 x 10-7kgC-1]
- A. 5.4 min
- B. 10.8 min
- C. 15.0 min
- D. 20.0 min
from the diagram above, the inductive reactance and the resistance R are respectively
- A. 50Ω and 45Ω
- B. 25Ω and 51Ω
- C. 20Ω and 50Ω
- D. 10Ω and 50Ω
During the nuclear reaction described by
| 235 | W → | 235 | X→ | 231 | Y |
| 92 | 93 | 91 |
the particles emitted are respectively
- A. α and α
- B. α and β
- C. β and β
- D. β and α
Which of the following will be applied when a metal Y is used to electroplate another metal X in electrolysis?
- A. X is the anode and very high current is used
- B. X is the anode and Y is the cathode
- C. Y is the cathode and X is the anode
- D. Y is the anode and very high current is used
If the threshold frequency for tungsten is 1.3 x 1015Hz, what is its work function?
[H = 6.6 x 10-34 Js]
- A. 8.58 x 10-19 J
- B. 8.50 x 10-15 J
- C. 8.58 x 10-17 J
- D. 8.85 x 10-18
The electrical properties of germanium can be altered drastically by the addition of impurity. This process is referred to as
- A. saturation
- B. bonding
- C. amplification
- D. dopping
A radioactive isotope has a decay constant of 10-5s4. Calculate half life
- A. 6.93 x 10-5s
- B. 6.93 x 105s
- C. 6.93 x104s
- D. 6.93 x 10-4s
The bond between silicon and germanium is
- A. covalent
- B. ionic
- C. dative
- D. electrovalent
Which of the following materials has an increase in resistance with temperature?
- A. water
- B. metals
- C. wood
- D. electrolyte