EdgineerX

2951. The internal energy of an ideal gas depends only on its

A. pressure B. temperature C. density D. volume E. molar mass

2952. Heat flows spontaneously from a body at higher temperature to one at lower temperature. This is a statement of the

A. first law B. third law C. law of conservation of mass D. zeroth law E. second law

2953. The electric field intensity at distance r from a point charge q is

A. k q divided by r B. k divided by q r C. k q divided by r squared D. k q r squared E. k q r

2954. Potential difference between two points is defined as the work done per unit charge in moving a charge

A. to infinity always B. along a field line only C. around a closed loop D. through a conductor only E. between the two points

2955. Millikan's oil drop experiment determined the

A. mass of the proton B. charge on the electron C. Planck constant D. speed of light E. charge to mass ratio of the electron

2956. Conventional current is taken to flow

A. only in semiconductors B. in the direction of electron flow C. opposite to the direction of electron flow D. from low to high potential in the external circuit E. perpendicular to electron flow

2957. Current density in a conductor is defined as the current per unit

A. length B. cross sectional area C. volume D. potential difference E. time

2958. The electromotive force of a cell is the energy supplied per unit charge in driving it

A. through the internal resistance only B. across the terminals at open circuit only C. in the reverse direction D. through the external resistance only E. around the complete circuit

2959. Two identical bulbs are connected first in series and then in parallel across the same supply. They are brighter

A. only if the supply is AC B. equally in both cases C. in parallel D. in series E. only if the supply is DC

2960. A fuse protects a circuit because it is made of a wire with

A. low melting point and suitable resistance so that it melts on excess current B. high melting point and low resistance C. the same rating as the supply D. zero resistance E. infinite resistance

2961. The polarity of the ends of a current carrying solenoid is found using the

A. Lenz law only B. inverse square law C. left hand rule for force D. right hand grip rule E. parallel axis theorem

2962. Relative permeability of a medium is defined as the ratio of its permeability to that of

A. iron B. the sample itself C. water D. air at high pressure E. free space

2963. Magnetic field lines form closed loops, which shows that

A. magnetic fields do no work B. magnetic fields are conservative C. the field has no direction D. magnetic monopoles have not been observed E. the field is always uniform

2964. A charged particle at rest in a magnetic field experiences

A. a torque only B. a force along the field C. no magnetic force D. an accelerating force E. a force perpendicular to the field

2965. Electromagnetic braking in trains relies on

A. compressed air alone B. friction pads only C. eddy currents induced in a moving metal disc or rail D. permanent magnets repelling E. chemical reaction

2966. A device that generates alternating current from mechanical rotation is called an

A. inverter B. electrolyser C. electromagnet D. amplifier E. alternator

2967. The induced emf in a coil is greatest when the rate of change of flux is

A. negative only B. maximum C. zero D. equal to the flux E. constant and small

2968. The inductive reactance of a coil of inductance L at frequency f is

A. f L B. 2 pi L divided by f C. L divided by 2 pi f D. 2 pi f L E. 1 divided by 2 pi f L

2969. A capacitor in a circuit

A. blocks direct current and passes alternating current B. passes both equally C. passes direct current and blocks alternating current D. blocks both E. behaves as a pure resistance

2970. In an LC circuit, energy oscillates between

A. the resistor and the source B. the magnetic field of the inductor and the electric field of the capacitor C. two capacitors only D. the source and earth E. heat and light

2971. In amplitude modulation, the quantity of the carrier wave that is varied in step with the signal is its

A. phase B. frequency C. wavelength only D. speed E. amplitude

2972. The rms value of an alternating current is defined as the steady direct current that would

A. produce the same heating effect in a given resistance B. have the same frequency C. have zero average D. have the same peak value E. flow for the same time

2973. Beyond the yield point, a metal specimen

A. becomes perfectly elastic B. obeys Hooke's law C. fractures immediately D. undergoes appreciable permanent deformation E. returns exactly to its original length

2974. Shear strain is measured as

A. the angle through which a face is displaced B. the change in volume divided by the original volume C. the change in length divided by the original length D. stress divided by strain E. force divided by area

2975. Conduction in a pure semiconductor arising from thermally generated electron hole pairs is described as

A. extrinsic B. intrinsic C. ionic D. superconducting E. metallic

Mixed Practice