In the AC circuit diagram above, the resonance frequency is
- A. 5000π Hz
- B. 2500π Hz
- C. 5000/π Hz
- D. 2500/π Hz
The total resistance measured at PQ in the diagram above is
- A. 18.0Ω
- B. 11.0Ω
- C. 4.0Ω
- D. 2.0Ω
A body on the ground is acted on by a force of 10N at a point P as shown in the fig above. What force is needed to stop the body from moving eastwards?
- A. 5N in the direction of east
- B. 5N in the diretion of west
- C. 5V3N in the direction of west
- D. 10N in the southwest direction
In photoelectric effect, electrons will leave the metal surface when illuminated by light of appropriate frequency if the photon energy is
- A. greater than the work function
- B. less than the work function
- C. equal to the work function
- D. equal to the maximium kinetic energy of the electron
In a nuclear fusion experiment, the loss of mass amounts to 1.0 x 10-6kg. The amount of energy obtained from the fusion is
- A. 3.0 x 10-4J
- B. 3.0 x 10-1J
- C. 9.0 x 104J
- D. 9.0 x 1010J
The electrochemical equivalent of a metal is 1.3 x 10-7kgC-1. The mass of the metal which 2.0 x 104C of electricity will deposit from a suitable electrolyte is
- A. 6.5 x 10-2kg
- B. 2.6 x 10-2kg
- C. 6.5 x 10-3kg
- D. 2.6 x 10-3kg
A transformer which can produce 8V from a 240v a.c. supply, has an efficiency of 80%. If the current in the secondary coil is 15A, calculate the current in the primary coil.
- A. 0.625A
- B. 1.600A
- C. 2.500A
- D. 6.250A
Electricity is supplied to a school along a cable of total resistance 0.5\(\Omega\) with the maximum current drawn from the mains as 100A. The maximum energy dissipated as heat for 1 hr is
- A. 3.6 x 103J
- B. 5.0 x 103J
- C. 3.0 x 105J
- D. 1.8 x 107J
The iron core of an induction coil is made from bundles of wire so as to
- A. minimize eddy-currents
- B. generate eddy-current
- C. prevent sparking at the contact breaker
- D. get the greatest posible secondary voltage
A parallel plate capacitor has a common plate area of 5 x 10\(^{-8}\)m2 and plate separation of 2 x 10\(^{-3}\)m, Assuming free space,
What is the capacitance? [\(\varepsilon\)o = 9.0 X 10-\(^{-12}\)C2N-1m-2]
- A. 2.25 x 10-17F
- B. 4.50 x 10-17F
- C. 2.25 x 10-16F
- D. 4.50 x 10-16F
Find the work done in moving a 2 C charge between two points X and Y in an electric field if the potential difference is 100 volts
- A. 50J
- B. 100J
- C. 200J
- D. 400J
Which of the following can be used to reduce local action in a Laclanche cell?
- A. A carbon rod as the positive pole
- B. Pure zinc as the negative pole
- C. Potassium permanganate solution in contact with the positive pole
- D. common salt solution
An ebonite rod rubbed with fur attracts a glass rod rubbed with silk because
- A. ebonite has a negative charge while glass has a positive charge
- B. ebonite has a positive charge while glass has a negative charge
- C. both have negative charges
- D. both have positive charges
The force of repulsion between two point positive charges 5\(\mu\)C and 8\(\mu\)C separated at a distance of 0.02m apart is. [\(\frac{1}{4{\pi}{\varepsilon}_o}\) = 9 x 10\(^9\)Nm\(^2\)C\(^{-2}\)]
- A. 1.8 x 10-10N
- B. 9.0 x 10-8N
- C. 9.0 x 102N
- D. 4.5 x 103N
Which of the following are true about the infra-red radiation? i. it is invisible ii. it is called heat ray iii. its frequency is higher than that of blue light iv. it travels as a transverse wave
- A. i, ii, iii and iv
- B. i, ii, iv only
- C. i, iii, iv only
- D. ii, iii, iv only
A man wears convex lens glasses of focal length 30cm in order to correct his eye defect. instead of the optimum 25cm, his least distance of distinct vision is
- A. 14cm
- B. 28cm
- C. 75cm
- D. 150cm
The displacement d produced in a glass block of thickness t and refractive index n when an object is viewed through it is
- A. t – n
- B. t (1 + 1/n)
- C. t (1-1/n)
- D. t (1/n - 1)
The most suitable type of mirror used for the construction of the search light is the?
- A. concave mirror
- B. convex mirror
- C. spherical mirror
- D. parabolic mirror
An object is placed in front of two plane mirrors inclined at an angle of 0o. If the total number of images formed is 7, Find the value of \(\theta\)
- A. 30o
- B. 45o
- C. 51o
- D. 90o
An object 0 lies at a distance m in front of concave mirror of focal length f. If m < f, then the final image obtained will be
- A. virtual and diminished
- B. magnified and erect
- C. real and inverted
- D. diminished and erect
In a resonance tube experiment, if the fundamental frequency of the vibrating air column is 280Hz, the frequency of the third overtone is
- A. 70Hz
- B. 840Hz
- C. 1120Hz
- D. 1960Hz