Two resistors 5Ξ© and 10Ξ© are arranged first in series and later in parallel to a 24V source, the ratio of total power dissipated in the series and parallel arrangements respectively is
- A. 5:3
- B. 1:50
- C. 50:1
- D. 3:5
- E. No Correct Option
In an A.C circuit, the ratio of r.m.s value to peak value of current is
- A. 2
- B. \( \frac{1}{2} \)
- C. \( \frac{1}{\sqrt{2}} \)
- D. \( \sqrt{2} \)
In Homes, electrical appliances and lamps are connected in parallel because
- A. Parallel connections do not heat up the wires
- B. independence switches can be used
- C. less current will be used
- D. less voltage will be used
If the volume of a gas increases steadily as the temperature decreases at constant pressure, the gas obeys
- A. Graham's Law
- B. Boyle's Law
- C. Pressure law
- D. Charles Law
- E. No Correct Option
In the circuit above, three resistors, 2Ξ©, 4Ξ© and 12Ξ© are connected in parallel and a 12V battery is connected across the combination. The current flowing through the 12Ξ© resistors is
- A. 14.4 A
- B. 1.0 A
- C. 3.2 A
- D. 9.6 A
A length of wire has a frequency of 225Hz when stretched by a force of 225N. If the force increased to 324N, what is the new frequency of vibration?
- A. 270 Hz
- B. 512 Hz
- C. 488 Hz
- D. 356 Hz
An image in a convex lens is upright and magnified 3 times. If the focal length of the lens is 15 cm, what is the object distance?
- A. 10 cm
- B. 25 cm
- C. 16 cm
- D. 14 cm
The correct expression for the potential at a point distance r from a charge q in an electric field is?
- A. _q24ΟΞ΅or2
- B. _q24ΟΞ΅or
- C. _q4ΟΞ΅or2
- D. \(\frac{q}{4ΟΞ΅_or}\)
The diagram above show the positions of a cone. The position which can be described as neutral equilibrium is represented as
- A. Z only
- B. X only
- C. Y and Z
- D. Y and X
The diagram above shows two vectors at right angles to each other. The value of the resultant vector is
- A. 14.0 N
- B. 10.0 N
- C. 12.0 N
- D. 13.0 N
Which of the following will be applied when a metal Y is used to electroplate another metal X in electrolysis?
- A. X is the anode and very high current is used
- B. X is the anode and Y is the cathode
- C. Y is the cathode and X is the anode
- D. Y is the anode and very high current is used
If the threshold frequency for tungsten is 1.3 x 1015Hz, what is its work function?
[H = 6.6 x 10-34 Js]
- A. 8.58 x 10-19 J
- B. 8.50 x 10-15 J
- C. 8.58 x 10-17 J
- D. 8.85 x 10-18
The electrical properties of germanium can be altered drastically by the addition of impurity. This process is referred to as
- A. saturation
- B. bonding
- C. amplification
- D. dopping
A radioactive isotope has a decay constant of 10-5s4. Calculate half life
- A. 6.93 x 10-5s
- B. 6.93 x 105s
- C. 6.93 x104s
- D. 6.93 x 10-4s
The bond between silicon and germanium is
- A. covalent
- B. ionic
- C. dative
- D. electrovalent
Which of the following materials has an increase in resistance with temperature?
- A. water
- B. metals
- C. wood
- D. electrolyte
Two inductors of inductance 4 II and 8 II are arrange in series and a current of 10 A is passed through them. What is the energy stored in them?
- A. 600 J
- B. 50 J
- C. 133 J
- D. 250 J
Under which of the following conditions do gases conduct electricity?
- A. Low presssure and low p.d
- B. low pressure and high p.d
- C. high pressure an low p.d
- D. high pressure and high p.d
If the charge of electricity is K wh is N4, what is the cost of operating an electrical appliance rated 250 v,2 A for six hours?
- A. N28
- B. N12
- C. N16
- D. N24
In measuring high frequency a.c, the instrument used is the
- A. d.c ammeter
- B. moving coil ammeter
- C. moving iron ammeter
- D. hot wire ammeter
Which of the following is a property of steel?
- A. it cannot retain its magnetism longer than iron
- B. it can be used for making temporary magnets
- C. it can be used for making permanent magnets
- D. it can easily be magnetized and demagnetized