MCQOPTIONS
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MCQOPTIONS
This section includes 26 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The mass excess for U-235 is |
| A. | 0.043 u |
| B. | 0.034 u |
| C. | 0.06 u |
| D. | 0.05 u |
| Answer» B. 0.034 u | |
| 2. |
The steady d.c voltage is also known as |
| A. | root mean square velocity |
| B. | square velocity |
| C. | velocity |
| D. | root velocity |
| Answer» B. square velocity | |
| 3. |
The number of oscillations per unit time is |
| A. | wavelength |
| B. | amplitude |
| C. | period |
| D. | frequency |
| Answer» E. | |
| 4. |
In an ac circuit, the instantaneous values of e.m.f. and current are e = 200 sin 314 t volt and\[i=\sin \,\left( 314t+\frac{\pi }{3} \right)\] ampere. The average power consumed in watt is [NCERT 1990; RPMT 1997] |
| A. | 200 |
| B. | 100 |
| C. | Kinetic energy of electron in n = 2 orbit is less than that in n = 1 orbit |
| D. | 25 |
| Answer» D. 25 | |
| 5. |
The frequency for which a \[5\,\mu F\] capacitor has a reactance of \[\frac{1}{1000}\] ohm is given by [MP PET 1997] |
| A. | \[\frac{100}{\pi }MHz\] |
| B. | \[\frac{1000}{\pi }Hz\] |
| C. | 1.06 Å |
| D. | 1000 Hz |
| Answer» B. \[\frac{1000}{\pi }Hz\] | |
| 6. |
In the circuit shown below, what will be the readings of the voltmeter and ammeter [RPMT 1996] |
| A. | 800 V, 2A |
| B. | 300 V, 2A |
| C. | If assertion is true but reason is false. |
| D. | 100 V, 2A |
| Answer» D. 100 V, 2A | |
| 7. |
In the adjoining figure the impedance of the circuit will be |
| A. | 120 ohm |
| B. | 50 ohm |
| C. | Zero |
| D. | 90 ohm |
| Answer» D. 90 ohm | |
| 8. |
A virtual current of 4A and 50 Hz flows in an ac circuit containing a coil. The power consumed in the coil is 240 W. If the virtual voltage across the coil is 100 V its inductance will be |
| A. | \[\frac{1}{3\pi }\]H |
| B. | \[\frac{1}{5\pi }H\] |
| C. | 15 |
| D. | \[\frac{1}{9\pi }H\] |
| Answer» C. 15 | |
| 9. |
In a certain circuit current changes with time according to \[i=2\sqrt{t}.\] r.m.s. value of current between \[t=2\] to \[t=4s\] will be |
| A. | \[3A\] |
| B. | \[3\sqrt{3}A\] |
| C. | \[{{0}^{o}}\] |
| D. | \[(2-\sqrt{2})A\] |
| Answer» D. \[(2-\sqrt{2})A\] | |
| 10. |
When 100 volts dc is supplied across a solenoid, a current of 1.0 amperes flows in it. When 100 volts ac is applied across the same coil, the current drops to 0.5 ampere. If the frequency of ac source is 50 Hz, then the impedance and inductance of the solenoid are [CPMT 1990] |
| A. | 200 W and 0.55 henry |
| B. | 100 Wand 0.86 henry |
| C. | \[{{10}^{4}}{{m}^{-1}}\] |
| D. | 100 W and 0.93 henry |
| Answer» B. 100 Wand 0.86 henry | |
| 11. |
Assertion : If the frequency of alternating current in an ac circuit consisting of an inductance coil is increased then current gets decreased. Reason : The current is inversely proportional to frequency of alternating current. |
| A. | If both assertion and reason are true and the reason is the correct explanation of the assertion. |
| B. | If both assertion and reason are true but reason is not the correct explanation of the assertion. |
| C. | \[1.45\mu m\]and \[4.04\mu m\] |
| D. | If the assertion and reason both are false. |
| E. | If assertion is false but reason is true. |
| Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion. | |
| 12. |
The resistance of a coil for dc is in ohms. In ac, the resistance [CPMT 1987] |
| A. | Will remain same |
| B. | Will increase |
| C. | Proton |
| D. | Will be zero |
| Answer» C. Proton | |
| 13. |
The maximum value of a.c. voltage in a circuit is 707V. Its rms value is [MP PET 2005] |
| A. | 70.7 V |
| B. | 100 V |
| C. | \[1.09\times {{10}^{9}}per\ m\] |
| D. | 707 V |
| Answer» D. 707 V | |
| 14. |
A 280 ohm electric bulb is connected to 200V electric line. The peak value of current in the bulb will be [MP PET 2002] |
| A. | About one ampere |
| B. | Zero |
| C. | From n = 4 to n = 2 |
| D. | About four ampere |
| Answer» B. Zero | |
| 15. |
An ac supply gives 30 V r.m.s. which passes through a 10\[\Omega \] resistance. The power dissipated in it is [AMU (Med.) 2001] |
| A. | \[90\sqrt{2}\,W\] |
| B. | \[90\,W\] |
| C. | 13.6 V |
| D. | \[45\,W\] |
| Answer» C. 13.6 V | |
| 16. |
An inductor L and a capacitor C are connected in the circuit as shown in the figure. The frequency of the power supply is equal to the resonant frequency of the circuit. Which ammeter will read zero ampere [DCE 2002] |
| A. | \[{{A}_{1}}\] |
| B. | \[{{A}_{2}}\] |
| C. | R to S |
| D. | None of these |
| Answer» D. None of these | |
| 17. |
In a LCR circuit capacitance is changed from C to 2C. For the resonant frequency to remain unchanged, the inductance should be change from L to [AIEEE 2004] |
| A. | 4L |
| B. | 2L |
| C. | 9/ 4 |
| D. | L/4 |
| Answer» D. L/4 | |
| 18. |
In a ac circuit of capacitance the current from potential is [CPMT 2003] |
| A. | Forward |
| B. | Backward |
| C. | 9 R |
| D. | None of these |
| Answer» B. Backward | |
| 19. |
The power factor of an ac circuit having resistance (R) and inductance (L) connected in series and an angular velocity \[\omega \] is [AIEEE 2002; MP PET 2000] |
| A. | \[R/\omega L\] |
| B. | \[R/{{({{R}^{2}}+{{\omega }^{2}}{{L}^{2}})}^{1/2}}\] |
| C. | 4r |
| D. | \[R/{{({{R}^{2}}-{{\omega }^{2}}{{L}^{2}})}^{1/2}}\] |
| Answer» C. 4r | |
| 20. |
In an ac circuit, the power factor [Roorkee 2000] |
| A. | Is zero when the circuit contains an ideal resistance only |
| B. | Is unity when the circuit contains an ideal resistance only |
| C. | 13.6 eV |
| D. | Is unity when the circuit contains an ideal inductance only |
| Answer» D. Is unity when the circuit contains an ideal inductance only | |
| 21. |
A 220 V, 50 Hz ac source is connected to an inductance of 0.2 H and a resistance of 20 ohm in series. What is the current in the circuit [MNR 1998; JIPMER 2001, 02] |
| A. | 10 A |
| B. | 5 A |
| C. | \[\frac{{{e}^{3}}}{2{{\varepsilon }_{0}}hc}\] |
| D. | 3.33 A |
| Answer» E. | |
| 22. |
In a series resonant circuit, the ac voltage across resistance R, inductance L and capacitance C are 5 V, 10 V and 10 V respectively. The ac voltage applied to the circuit will be [KCET 1994] |
| A. | 20 V |
| B. | 10 V |
| C. | \[6.75\times {{10}^{13}}\,Hz\] |
| D. | 25 V |
| Answer» D. 25 V | |
| 23. |
In a region of uniform magnetic induction \[B={{10}^{-2}}\,tesla\], a circular coil of radius 30 cm and resistance p2 ohm is rotated about an axis which is perpendicular to the direction of B and which forms a diameter of the coil. If the coil rotates at 200 rpm the amplitude of the alternating current induced in the coil is [CBSE PMT 1990] |
| A. | 4p2 mA |
| B. | 30 mA |
| C. | \[{{e}^{2}}c/2\pi h\] |
| D. | 200 mA |
| Answer» D. 200 mA | |
| 24. |
An inductance of 1 mH a condenser of 10 mF and a resistance of 50 W are connected in series. The reactances of inductor and condensers are same. The reactance of either of them will be |
| A. | 100 W |
| B. | 30 W |
| C. | 8 : 1 |
| D. | 10 W |
| Answer» E. | |
| 25. |
A 20 volts ac is applied to a circuit consisting of a resistance and a coil with negligible resistance. If the voltage across the resistance is 12 V, the voltage across the coil is [MP PMT 1989; RPMT 1997] |
| A. | 16 volts |
| B. | 10 volts |
| C. | 5.6 E |
| D. | 6 volts |
| Answer» B. 10 volts | |
| 26. |
An inductive circuit contains resistance of 10 W and an inductance of 20 H. If an ac voltage of 120 V and frequency 60 Hz is applied to this circuit, the current would be nearly |
| A. | 0.32 amp |
| B. | 0.016 amp |
| C. | \[3.15\times {{10}^{-34}}\] |
| D. | 0.80 amp |
| Answer» C. \[3.15\times {{10}^{-34}}\] | |