The frequency of the wave in the diagram above is
- A. 0.17 Hz
- B. 0.25 Hz
- C. 1.57 Hz
- D. 1.05 Hz
A progressive wave equation is represented by y = a sin(150 ฯt – ฯx/4). if the phase difference of a progressive wave is 45ยฐ, the value of x in the equation is
- A. 3 cm
- B. 4 cm
- C. 1 cm
- D. 2 cm
An engine of a car of power 80 kW moves on a rough road with a velocity of 32 m\(s^-1\). The forces required to bring it to rest is
- A. 2.56 x 106N
- B. 2.50 x 106N
- C. 2.80 x 103N
- D. 2.50 x 103N
A shooter wants to fire a bullet in such a way that its horizontal range is equal to three times its maximum height. At the what angle should he fire the bullet to achieve this?
- A. 68o
- B. 53o
- C. 30o
- D. 45o
In a gas experiment, if the volume of the gas is plotted against the reciprocal of the pressure, the unit of the slope of the resulting curve is
- A. force
- B. temperature
- C. power
- D. work
A mirror of weight 75N is hung by a cord from a hook on the wall. If the cord makes an angle of 30o with horizontal, the tension in the cord is
- A. 100N
- B. 1500N
- C. 250N
- D. 150N
In the diagram above, the pressure of the gas is
- A. 86 cm of mercury
- B. 66 cm of mercury
- C. 96 cm of mercury
- D. 76 cm mercury
The diagram above represents the stress-strain graph for a typical metal rod. What does the X represent?
- A. Breaking point
- B. Yield point
- C. Elastic limit
- D. Proportional limit
A radioactive substance has a half-life of 20 days what fraction the original radiation nuclei will remain after 80 days?
- A. (1)/32
- B. (1)/16
- C. (1)/ 8
- D. (1)/4
A 120 V, 60 W lamp is to be operated on 220 V a.c. the supply mains. calculate the values of non-inductive resistance that would be required to ensure that the lamp is run on current value.
- A. 100 โฆ
- B. 200 โฆ
- C. 300 โฆ
- D. 500 โฆ
The instrument that measures both a.c and d.c is?
- A. a current balance
- B. a moving current ammeter
- C. a moving iron ammeter
- D. an inverter
A 40 kW electric cable is used to transmit electricity through a resistor of resistance 2.0โฆ at 800 V. The power loss as internal energy is?
- A. 4.0 x 102W
- B. 5.0 x 102W
- C. 4.0 x 103W
- D. 5.0 x 103W
A conductor has a diameter of 1.00 mm and length 2.00m. if the resistance of the material is 0.1โฆ, its resistivity is?
- A. 2.55 x 105 โฆm
- B. 2.55 x 102 โฆm
- C. 3.93 x 10-6 โฆm
- D. 3.93 x 10-8 โฆm
If two charged plates are maintained at a potential difference of 3 kv, the work done in taking a charge of 600 ยตC across the field is?
- A. 0.8 J
- B. 1.8 J
- C. 9.0 J
- D. 18.0 J
A person can focus objects when they lie beyond 75 cm from his eyes. The focal length of the lens required to reduce his least distance of distinct vision to 25 cm is?
- A. 37.50 cm
- B. 75.00 cm
- C. 18.75
- D. 25.00 cm
The wavelength of the first overtone of a note in a closed pipe of length 33 cm is?
- A. 33 cm
- B. 44 cm
- C. 22 cm
- D. 17 cm
Non-luminous object can be seen because they
- A. reflect light
- B. are near
- C. are polished
- D. emit light
A submarine is observed to rise from a real depth off 80 m to 60 m in water. calculate the change in apparent depth.
[Refraction index of water (4)/3]
- A. 45 m
- B. 80 m
- C. 15 m
- D. 60 m
An object placed 10cm from a concave mirror of focal length 5cm would have its image
- A. at the centre of convature
- B. at the radius of curvature
- C. at infinity
- D. 10 cm from the focus
A p-n junction diode is used as?
- A. a rectifier in a d.c circuit
- B. an amplifier in d.c circuit
- C. an anplifier in an a.c circuit
- D. a rectifier in an a.c circuit
A certain manufacturer wishes to make an n-type semiconductor. Which materials would he select for doping?
- A. boron and antimony
- B. boron and sodium
- C. aluminium and indium
- D. arsenic and antimony