In the above circuit, The fuse wire melts when
- A. K is Opened
- B. K is closed
- C. the 14 ohm resistor is doubled with k closed
- D. the 6 ohm resistor is doubled with k closed
The net capacitance of the circuit shown above is
- A. 8.0ยตF
- B. 6.0ยตF
- C. 4.0ยตF
- D. 2.0ยตF
Th internal resistance of each of the cells E1 and E2 Shown in the figure above is 2 Ohm. Calculate the total current in the circuit
- A. 0.80A
- B. 0.50A
- C. 0.40A
- D. 0.004A
A body is under action of a force F such that the force displacement graph of the body is semi circular as shown above. The work done on the body by the force in moving through 24 meters is
- A. 36ฯ J
- B. 72ฯ J
- C. 144ฯ J
- D. 288ฯ J
Find the tension T1 in the diagram above if the system is in equilibrium
[G = 10ms-2]
- A. 200/โ3N
- B. 100/โ3N
- C. 300/โ3N
- D. 100N
Which of the following phenomena is called photoelectric effect?
- A. high energy electrons impinge on a metalic anode which then emits photons
- B. a high energy photon emits photons as it slowed down
- C. a metal absorbs quanta of light and then emits electrons
- D. Two electrons are created from a quantum of light
Which of the following are True for \(\alpha\)-decay. i. mass number, decrease by four. ii. Atomic number decreases by two. iii. mass number does not change.
- A. i and ii only
- B. ii and iii only
- C. i and iii only
- D. i, ii, and iii only
In a nuclear fusion process, four protons each of mass Mp were fused to produce a nucleus X of mass Mx. Which of the following equations is CORRECT?
- A. 4Mp > Mx
- B. 4Mp = Mx
- C. 4Mp < Mx
- D. Mp > Mx
4g of a radioactive material of half-life 10 days is spilled on a laboratory floor. How long would it take to disintegrate 3.5g of the material?
- A. 1\(\frac{1}{4}\) days
- B. 8\(\frac{1}{4}\) days
- C. 30 days
- D. 80 days
When an atom loses or gains a charge, it becomes
- A. an electron
- B. an ion
- C. a neutron
- D. a proton
which of the following statements are TRUE of isotopes? i. isotopes of an element have the same chemical properties because they have the same number of electrons. ii. isotopes of elements are normally separated using physical properties. iii. isotopes of an element have the same number of protons in their nuclei.
- A. i and ii only
- B. i and iii only
- C. ii and iii only
- D. i, ii, and iii
The electrochemical equivalent of platinum is 5.0 x 10-7kgC-1 to plate-out 1.0kg of platinum, a current of 100A must be passed through an appropriate vessel for
- A. 5.6 hours
- B. 56 hours
- C. 1.4 x 104 hours
- D. 2.0 x 104 hours
If a current carrying coil is mounted on a metal frame, the back e.m.f. induced in the coil causes
- A. inductance
- B. eddy currents
- C. elecro-magnetism
- D. dipole moment
To convert an alternating current dynamo into a direct current dynamo, the
- A. number of turns in the coil is increased
- B. strength of the field magnet is increased
- C. slip rings are replaced with a split ring commutator
- D. coil is wound on a soft iron armature
An equipment whose power is 1500W and resistance is 375 ohms would draw a current of
- A. 0.10A
- B. 2.00A
- C. 4.00A
- D. 77.5A
Which of the following obeys Ohm’s Law?
- A. Glass
- B. Diode
- C. All electrolytes
- D. All metals
A moving coil galvanometer of 300\(\Omega\) resistance gives full scale deflection for 1.0mA. The resistance R, of the shunt that is required to convert the galvanometer into a 3.0A ammeter is
- A. 899.70\(\Omega\)
- B. 10.00\(\Omega\)
- C. 0.10\(\Omega\)
- D. 0.01\(\Omega\)
The function of the system of granulated carbon mixed with manganese (IV) oxide in a Letanche cell is to
- A. increase the e.m.f. of the cell to 2.0V
- B. prevent local action in the cell
- C. prevent polarisation in the cell
- D. make the cell black and hence a good radiator
An insulated rod when rubbed with a material acquires
- A. a negative charge if it is made of glass and rubbed with silk
- B. no charge if it is made of glass and rubbed with fur
- C. no charge if it is made of copper and rubbed with silk
- D. a positive charge if it is made of copper and rubbed with fur
Which of the following statements is CORRECT about the earth’s magnetic field?
- A. the angle of dip is the angle which a freely suspended magnet makes with the vertical
- B. the angle of declination is the angle between the magnetic meridian and the geographic meridian
- C. the angle of declination is the angle which a magnetic compass makes with the magnetic meridian
- D. the angle of inclination is the difference between the angle of dip and the angle of declination
When the bottom tip of a vibrating tuning fork is held in contact with a wooden box, a louder sound is heard. This phenomenon is known as
- A. beats
- B. echoing
- C. resonance
- D. reverberation