181.X- rays cannot be used
- A. to take photographs of bone structure in the body
- B. to detect finger prints
- C. to detect flaws in metal castings
- D. to detect alterations to works of art
182.1 farad is equivalent to:
- A. 1 coulomb/volt
- B. 1 volt/coulomb
- C. 1 joules/coulomb
- D. 1 ampere/sec
183.A 0 - 10mA galvanometer with a coil resistance of 30 ohm can be converted to a 0-10A ammeter by using
- A. 0.03ohm series resistor
- B. 9.99ohm shunt resistor
- C. 0.03ohm shunt resistor
- D. 9.99ohm series resistor
184.A battery has an internal resistance of 4 and an emf of 12V. The terminal voltage when a load of 20 Ω is connected across it is:
- A. 4 V
- B. 10 V
- C. 20 V
- D. 2 V
185.A magnet cannot be demagnetized by
- A. heating
- B. hammering
- C. chemical treatment
- D. the use of solenoid through which an alternating current is flowing
186.An a.c voltage is connected to an RLC series circuit of resistance 5 Ω, inductance 3 mH and a capacitance of 0.05 µF. Calculate the resonance frequency.
- A. 11.0 kHz
- B. 12.0 kHz
- C. 13.0 kHz
- D. 14.0 kHz
187.An electric heater converts 1KJ of electrical energy to heat energy every 2 second with 100% efficiency. The power produced is
- A. 0.5 KW
- B. 2 KW
- C. 1KW
- D. 10W
188.Complete the following statement: The electromotive force is
- A. the maximum potential difference between the terminals of a battery
- B. the force that accelerates electrons through a wire when a battery is connected to it
- C. the force that accelerates protons through a wire when a battery is connected to it
- D. the maximum capacitance between the terminals of a battery
189.If a charged body is moving in a circle on a horizontal plane, what is the general direction of the resulting magnetic field?
- A. In the plane of the circle
- B. At an angle 45o to the plane of motion
- C. Along the perpendicular axis through the center of the circle
- D. Along the tangent to the circle
190.If a resistor is halved in magnitude and the potential across it is tripled, then the ratio of the old current to the new current is
191.The angle between the earth’s magnetic field and the horizontal is called angle of
- A. declination
- B. dip
- C. variation
- D. inclination
192.The basic difference between the galvanometer and the electric motor is
- A. The size of the magnetic fields
- B. The presence of hair springs in the galvanometer
- C. The soft iron armature in the galvanometer
- D. The couple formed on the parallel sides of the rectangular coil in the galvanometer
193.The electromotive force is in such a direction as to oppose the motion or charge producing it. This is a statement of
- A. Faraday’s Law
- B. Lenz Law
- C. Maxwell Law
- D. Ampere’s law
194.The potential difference across the ends of a wire is doubled in magnitude. If Ohm’s law is obeyed, one of the following statements concerning the resistance of the wire is true?
- A. The resistance is one half of its original value
- B. The resistance is twice its original value
- C. The resistance is not changed
- D. The resistance increases by a factor of four
195.The process of adding impurity to a semiconductor to increase its conductivity is called
- A. Doping
- B. Annealing
- C. Heating
- D. Hardening
196.Which if the following combinations consists of intrinsic properties of materials
- A. volume and density
- B. density and mass
- C. resistance and resistivity
- D. density and resistivity
197.Which of the following can be measured with a potentiometer:
- A. Emf of a secondary cell
- B. Resistivity of a wire
- C. Potential difference across a conductor
- D. Resistance of a wire
198.Which of the following devices is odd in the list ?
- A. thermocouple
- B. potentiometer
- C. d.c. generator
- D. solar cell
199.Which of the following is an essential physical property of the wires used for making fuses?
- A. high thermal conductivity
- B. low density
- C. low melting point
- D. low electrical resistivity
200.Which one of the following statements concerning the magnetic force on a charged particle in a magnetic field is true?
- A. It is a maximum if the particle is stationary
- B. It is a maximum if the particle moves parallel to the field
- C. It acts in the direction of motion for a positively charged particle
- D. It depends on the component of the particle's velocity that is perpendicular to the field