The radioisotope \( ^{235}_{92}U \) decays by emitting two alpha particles, three beta particles and a gamma ray. What is the mass and atomic number of the resulting element?
- A. 215 and 88
- B. 91 and 227
- C. 227 and 91
- D. 92 and 238
An object is weighed at different locations on the Earth. What will be the right observation?
- A. Both the mass and weight vary
- B. The weight is constant while the mass varies
- C. The mass is constant while the weight varies
- D. Both the mass and weight are constant
The process whereby a substance changes from a solid to liquid when heat is applied, is called?
- A. Evaporation
- B. Vaporization
- C. Fission
- D. Fusion
In Faradays law of electrolysis, a graph of the mass deposited against the quantity of electricity is plotted. The slope of the graph gives?
- A. the energy released
- B. the electrochemical equivalent
- C. the current flowing
- D. the charge released
In the diagram above, if the south-poles of two magnets strokes steel bar, the polarities at T and V will respectively be
- A. south and north
- B. north and south
- C. north and north
- D. south and south
In the diagram above, a 200 W bulb is lighted by a 240 V a.c mains supply. If 1kwh is sold at N40, the cost of keeping the bulb lighted for a day is?
- A. N1,920.00
- B. N192.00
- C. N19.20
- D. N1.92
Three 4Ω resistors connected in parallel have a potential difference of 16 V applied across them. What is the total current in the circuit?
- A. 14 A
- B. 12 A
- C. 10 A
- D. 8 A
The diagram above shows a balanced metre bridge, the value of x is
- A. 75.0 cm
- B. 66.7 cm
- C. 33.3 cm
- D. 25.0 cm
A cell of e.m.f 12V and internal resistance 4Ω is connected to an external resistor of resistance 2Ω. Find the current flow.
- A. 5 A
- B. 4 A
- C. 3 A
- D. 2 A
Three capacitors of capacitance 2μF, 4μFand 8μF are connected in parallel and a P.D of 6V is maintained across each capacitor, the total energy stored is?
- A. 2.52 x 10-6J
- B. 6.90 x 10-6J
- C. 2.52 x 10-4J
- D. 6.90 x 10-4J
THe velocity of sound in air at 16oC is 340ms-1. What will it be when the pressure is doubled and its temperature raised to 127ºC?
- A. 400 ms-1
- B. 4,000 ms-1
- C. 8,000 ms-1
- D. 160,000 ms-1
Two metals P and Q of length l1 and l2 are heated through the same temperature difference. If the ratio of the linear expansivities of P to Q is 2:3 and the ratio of lengths is 3:4. What is the ratio of increase in length of P to Q?
- A. 7:5
- B. 5:7
- C. 1:2
- D. 2:1
A bob of weight 0.1 N hangs from a massless string of length 50 cm. A variable horizontal force which increase from zero is applied to pull the bob until the string makes an angle of 60o with the vertical. The work done is?
- A. 0.500 J
- B. 0.250 J
- C. 0.050 J
- D. 0.025 J
The diagram above represents balls in an undulating surface. Which of the following option represents positions of stable equilibrium?
- A. III, IV and VIII
- B. II, V and VIII
- C. III, VI and IX
- D. I, IV and VII
The diagram above shows a velocity – time graph. The statement that is true about this motion is that the car?
- A. has no acceleration between point F and G
- B. decelerates between F and H
- C. has a constant soeed between points E and F
- D. Accelerates between points F and G
Which of the following is a pure semiconductor?
- A. carbon
- B. silicon
- C. transistor
- D. phosphorus
Transistors are used for the?
- A. rectification of signals
- B. conversion of a.c to d.c
- C. amplification of signals
- D. conversion of d.c to a.c
The ground stated energy for the hydrogen atom is 5.44 x 10-19J . If an electron drops from zero energy to ground state, calculate the frequency of the emitted radiation?
[h = 6.6 x 10-34 Js]
- A. 5.0 x 1016 Hz
- B. 2.0 x 1016 Hz
- C. 5.0 x 1015 Hz
- D. 2.0 x 1015 Hz
- E. No correct option
In a discharge tube, most of the gas is pumped out so that electricity is conducted at?
- A. low voltage
- B. steady voltage
- C. high pressure
- D. low pressure
In alternating current circuit at resonance, the angle of lead or lag is?
- A. π°
- B. (π)/2°
- C. (π)/3°
- D. 0°
Two inductors of inductance 5 mll and 15 mll are connected in series and a current of 5A flows through them. the total energy stored in the inductor is?
- A. 500.0J
- B. 250.0J
- C. 62.5J
- D. 50.0J
- E. no correct option