Jamb 1995 Physics Past Questions And Answers
Two parallel plates at a distance of 8.0 x 10-3m apart are maintained at a p.d of 600 volts with the negative plate earthed. What is the electric field strength?
- A. 4.8 Vm-1
- B. 75.0Vm-1
- C. 4800.0Vm-1
- D. 75000.0Vm-1
An alternating source is connected in series to a capacitor of capacity reactance \( 10^3 \sqrt{3} \) and a resistor of resistance 103 Ohms. The Impedance of the circuit is...
- A. \( 2000 \sqrt{3} \) Ohms
- B. 2000 Ohms
- C. \( 1000 \sqrt{3} \) Ohms
- D. 1000 Ohms
If a resistance is halved in value and the potential difference across it is tripled, then the ratio of the new current to the old one is
- A. 1 : 6
- B. 1 : 3
- C. 2 : 1
- D. 6 : 1
The primary winding of a transformer has 400 turns and its secondary has 100 turns. If a source of e.m.f. of 12V is applied to the primary, the secondary e.m.f. will be
- A. 3V
- B. 6V
- C. 24V
- D. 48V
A uniform rod PQ of length 1m and mass 2kg is pivoted at the end p. If load of 14N is placed at the center of the rod, find the force that should be applied vertically upwards at Q to maintain the rod at equilibrium horizontally [g = 10ms-2]
- A. 68N
- B. 28N
- C. 17N
- D. 7N
The purpose of a dielectric material in a parallel plate capacitor is to
- A. increase its capacitance
- B. decrease its capacitance
- C. insulate the plate from each other
- D. increase the magnetic field between the plates
The length of a displaced pendulum ball which passes its lowest point twice every seconds is [g = 10ms-2]
- A. 0.25 m
- B. 0.45 m
- C. 0.58m
- D. 1.00m
If the maximum voltage across a 100ohms resistor is 20V, then the maximum power it can dissipate is
- A. 5.00W
- B. 4.00W
- C. 2.00W
- D. 25W
Total eclipse of the sun occurs when the
- A. earth is between the moon and the sun
- B. sun is between the moon and the earth
- C. moon is between the sun and the earth
- D. ozone layer is threatened
The resultant capacitance in the fig below is
- A. 15.0μF
- B. 9.8μF
- C. 1.3μF
- D. 0.8μF