1. Two charges -q each are placed at the vertices A and B of an equilateral triangle ABC. If M is the mid-point of AB, the net electric field at C will point along:

(A) CA

(B) CB

(C) MC

(D) CM

2. A student has three resistors, each of resistance R. To obtain a resistance of (2/3)R, she should connect:

(A) All the three resistors in the series

(B) All the three resistors in parallel

(C) Two resistors in series and then this combination in parallel with the third resistor

(D) Two resistors in parallel and then this combination in series with the third resistor

3. A 1 cm straight segment of a conductor carrying 1 A current in the x-direction lies symmetrically at the origin of the Cartesian coordinate system. The magnetic field due to this segment at point (1m, 1m, 0) is:

 4. The magnetic field due to a small magnetic dipole of dipole moment 'M' at a distance 'r' from the centre along the axis of the dipole is given by:

 5. In the figure, X is a coil wound over a hollow wooden pipe.

A permanent magnet is pushed at a constant speed v from the right into the pipe and it comes out at the left end of the pipe. During the entry and the exit of the magnet, the current in the wire YZ will be from:

(A) Y to Z and then Z to Y

(B) Z to Y and then Y to Z

(C) Y to Z and then Y to Z

(D) Z to Y and then Z to Y

 6. The alternating current I in an inductor is observed to vary with time t as shown in the graph for a cycle. Which one of the following graphs is the correct representation of the waveform of voltage V with time t?

 7. A transformer is connected to a 200 V AC source. The transformer supplies 3000 V to a device. If the number of turns in the primary coil is 450, then the number of turns in its secondary coil is:

(A) 30

(B) 450

(C) 4500

(D) 6750

 8. Which one of the following statements is correct?

(A) Electric field due to static charges is conservative and field lines do not form closed loops.

(B) Electric field due to static charges is conservative and field lines form closed loops.

(C) Electric field due to static charges is non-conservative and field lines do not form closed loops.

(D) Electric field due to static charges is non-conservative and field lines form closed loops.

 9. A tub is filled with a transparent liquid to a height of 30.0 cm. The apparent depth of a coin lying at the bottom of the tub is found to be 16.0 cm. The speed of light in the liquid will be: 

(A) 1.6×108 m/s

(B) 2.0×108m/s

(C) 3.0×108m/s

(D) 2.5×108m/s

 10. Atomic spectral emission lines of the hydrogen atom are incident on a zinc surface. The lines which can emit photoelectrons from the surface are from:

(A) Balmer series

(B) Paschen series

(C) Lyman series

(D) Neither Balmer, nor Paschen, nor Lyman series

 11. The energy of an electron in a hydrogen atom in the ground state is -13.6 eV. Its energy in an orbit corresponding to quantum number n is -0.544 eV. The value of n is:

(A) 2

(B) 3

(C) 4

(D) 5

 12. When the resistance measured between p and n ends of a p-n junction diode is high, it can act as a/an:

(A) Resistor

(B) Inductor

(C) Capacitor

(D) Switch

 For Questions 13 to 16, two statements are given - one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below:
 

(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
(B) If both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
(C) If Assertion (A) is true but Reason (R) is false.
(D) If both Assertion (A) and Reason (R) are false.

13. Assertion (A): In a semiconductor diode, the thickness of the depletion layer is not fixed.
Reason (R): The thickness of the depletion layer in a semiconductor device depends upon many factors such as the biasing of the semiconductor

15. Assertion (A): Out of infrared and radio waves, the radio waves show more diffraction effect.
Reason (R): Radio waves have greater frequency than infrared waves.

16. Assertion (A): In an ideal step-down transformer, the electrical energy is not lost.
Reason (R): In a step-down transformer, voltage decreases but current increases.