Mixed Practice

Free set

Showing 2451 to 2475 of 3046 questions (page 99 of 122).

2451. Three capacitors of 2 microfarad each are connected in parallel. The equivalent capacitance is

A. 6 microfarad B. 0.67 microfarad C. 8 microfarad D. 2 microfarad E. 4 microfarad

2452. The electric field between two large parallel plates carrying equal and opposite charges is

A. radial B. inversely proportional to the separation squared C. uniform D. proportional to the distance from a plate E. zero

2453. The work done in moving a charge along an equipotential surface is

A. negative B. maximum C. infinite D. equal to qV E. zero

2454. One ampere is equivalent to

A. one joule per coulomb B. one volt per ohm second C. one coulomb per second D. one watt per volt second E. one coulomb per volt

2455. The power dissipated when 2 A flows through a 5 ohm resistor is

A. 0.4 W B. 40 W C. 2.5 W D. 10 W E. 20 W

2456. The terminal potential difference of a cell is less than its emf when

A. current is drawn from the cell B. the cell is being charged C. the external resistance is infinite D. the internal resistance is zero E. no current flows

2457. Below its critical temperature, the electrical resistance of a superconductor is

A. slightly reduced B. very large C. temperature dependent and rising D. zero E. negative

2458. In a series circuit, the quantity that is the same through every component is

A. resistance B. charge stored C. potential difference D. power E. current

2459. The direction of force on a current carrying conductor in a magnetic field is given by

A. Fleming's left hand rule B. Fleming's right hand rule C. Coulomb's law D. Lenz's law E. the corkscrew rule for potential

2460. A charged particle of mass m and charge q entering a magnetic field B perpendicularly with speed v moves in a circle of radius

A. mvB/q B. mv/qB C. qvB/m D. qB/mv E. mq/vB

2461. Two parallel wires carrying current in the same direction

A. exert no force B. attract only if the currents are unequal C. rotate about each other D. repel each other E. attract each other

2462. Faraday's law of induction states that the induced emf is proportional to the

A. current in the coil B. resistance of the coil C. rate of change of magnetic flux D. magnetic flux E. area of the coil only

2463. The peak emf produced by an AC generator with N turns, area A, rotating at angular frequency omega in field B is

A. NAB/omega B. NA omega C. AB omega D. NAB omega E. NAB

2464. The back emf in a DC motor is greatest when the motor is

A. disconnected B. just switched on C. reversed D. stalled E. running at full speed

2465. A step down transformer has 1000 turns in the primary and 100 in the secondary. If the primary voltage is 220 V, the secondary voltage is

A. 22 V B. 220 V C. 2.2 V D. 110 V E. 2200 V

2466. The negative sign in Faraday's law expresses

A. Gauss's law B. Lenz's law C. Ohm's law D. Ampere's law E. Coulomb's law

2467. Mutual inductance between two coils depends on

A. the current in the primary only B. the resistance of the secondary C. the voltage applied D. the relative geometry and number of turns of the coils E. the frequency of the supply only

2468. The impedance of a series RLC circuit is

A. R + XL + XC B. sqrt(R2 + XL2 + XC2) C. sqrt(R2 + (XL - XC)2) D. R (XL - XC) E. R - XL + XC

2469. The average value of a sinusoidal alternating current over one complete cycle is

A. the peak value B. 0.637 times the peak value C. zero D. 0.707 times the peak value E. twice the peak value

2470. The frequency of the domestic AC mains supply in Pakistan is

A. 220 Hz B. 50 Hz C. 100 Hz D. 60 Hz E. 25 Hz

2471. At resonance in a series RLC circuit, the impedance is

A. minimum and equal to R B. zero C. infinite D. maximum and equal to XL E. equal to XC

2472. In a purely capacitive AC circuit, the current

A. lags the voltage by 90 degrees B. is in phase with the voltage C. is zero D. leads the voltage by 90 degrees E. leads by 180 degrees

2473. The modulus that describes the deformation produced by a tangential force is

A. bulk modulus B. shear modulus C. Young's modulus D. compressibility E. Poisson's ratio

2474. At absolute zero, a pure intrinsic semiconductor behaves as

A. a p-type material B. a metal C. a conductor D. a superconductor E. an insulator

2475. A paramagnetic substance placed in a magnetic field is

A. unaffected B. strongly attracted C. weakly attracted D. permanently magnetized E. strongly repelled

Previous 1 2 … 97 98 99 100 101 … 121 122 Next

Get full access to the MCQ bank

Premium questions, timed mock tests, and detailed explanations.

See premium plans