A man walks 1km due east and then 1 km due north His displacement
- A. √2km N 45°E
- B. 1km N 30°E
- C. 1km N 15°E
- D. √2km N 60°E
Correct Option: Answer is A
Magnitude of displacement = √1²+1²=√2km
Direction of displacement, θ:
tanθ=1/1
θ=tan‾¹1
θ=45º
√2km N 45º E
2. The density of 400cm of palm oil was 0.9gcm-3 before frying. If the density of the oil was 0.6gm-3 after frying, assuming no loss of oil due to spilling, its new volume was?
- A. 1360cm3
- B. 600cm3
- C. 240cm
- D. 8000m3
Correct Option: Answer is B
\(Density= \frac{mass}{volume}\)
⇒ \(0.9gcm^{-3} = \frac{mass}{400cm^{3}} = 360g\)
without any loss in the frying process, we have
\(0.6gcm^{-3} = \frac{360g}{v}\)
\(v = \frac{360g}{0.6gcm^{-3}} = 600cm^{3}\)
3. Natural radioactivity consists of the emission of
- A. α- particles and β-rays
- B. α- particles and X-rays
- C. α- particles, β – rays and g-rays
- D. γ- rays and X-rays
Correct Option: Answer is C
Radioactivity is the spontaneous emission of radiation from atomic nuclei. This radiation can consist of alpha, beta, and gamma radiation.
4. Which of the following is true of an electrical charge?
- A. Positive charge means deficit electrons
- B. Negative charge means excess of electrons
- C. electric current means movement of electrons
- D. All of the above
Correct Option: Answer is D
5. Which of the following does NOT describe the Image formed by a plane minor?
- A. Erect
- B. Laterally inverted
- C. Same distance from mirror as object
- D. Magnified
Correct Option: Answer is D
Plane mirrors produce images with a number of distinguishable characteristics. Images formed by plane mirrors are virtual, upright, left-right reversed, the same distance from the mirror as the object’s distance, and the same size as the object.
6.
What is the resultant resistance of the circuit in the image shown?
- A. 8Ω
- B. 11Ω
- C. 4Ω
- D. 3.6Ω
Correct Option: Answer is A
Resistances in parallel:
1 / R=1 / 2Ω+1 / 2Ω=1Ω
R=1Ω
All resistances are now in series.
Resultant resistance = 3Ω+1Ω+4Ω=8Ω
7. Which of the following best describes the energy changes which take place when a steam engine drives a generator which lights a lamp?
- A. heat —-> Light—-> Sound —-> Kinetic
- B. Kinetic —-> Light —-> Heat —-> Electricity
- C. heat —-> Kinetic —-> Electricity —-> Heat and Light
- D. electricity —-> Kinetic —-> Heat —-> Light
Correct Option: Answer is C
The steam released powers an engine called a turbine, transforming heat energy from burning coal into mechanical energy, particularly kinetic energy that spins the turbine engine. The kinetic energy of the spinning turbine does work in a generator, a machine that turns this work into electric energy. The lamp uses this electricity to generate heat and light.
8. Cathode rays are
- A. High-energy electromagnetic waves
- B. protons
- C. neutrons
- D. streams of electrons
Correct Option: Answer is D
Cathode rays are streams of electrons observed in vacuum tubes.
9. A narrow beam of white light can be split up into different Colours by a glass prism. The correct explanation is that
- A. white light Is an electromagnetic wave
- B. the prism has all the colours of the white light
- C. different colours of white light travel with different speeds in glass
- D. white light has undergone total Internal reflection in the prism
Correct Option: Answer is C
10.
The diagram shown represents a block-and-tackle pulley system on which an effort of W Newtons supports a load of 120.0N. If the efficiency of the machine is 40, then the value of W is?
- A. 28.0
- B. 48.0N
- C. 233.0N
- D. 50.0N