An electric field \(\vec { E } =10x\hat { i } \) exists in a certain region of space. Then the potential difference V = V_o – V_A, where V_o is the potential at the origin and V_A is the potential at x = 2 m is _____.

(a)

10 V

(b)

-20 V

(c)

+20 V

(d)

-10 V

Van de Graaff generator produces an electrostatic potential difference of_______ volts.

(a)

10⁸

(b)

10⁹

(c)

10⁷

(d)

10¹⁰

When a point charge of 6mC is moved between two points in an electric field, the work done is 1.8 x 10^-5 J. The potential difference between the two points is

(a)

1.08 V

(b)

1.08 μV

(c)

3 V

(d)

30 V

Near a charged object A another earthed object B is placed. Charges are induced on B. If B is removed. After that the charge on A ________.

(a)

remains the same

(b)

decreases

(c)

increases

(d)

becomes zero

In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.

(a)

14 A

(b)

8 A

(c)

10 A

(d)

12 A

A square aluminum rod is 1 m long and 5 mm on edge. What must be the radius of another aluminum rod whose length is 1 m and which has the same resistance as that of square Aluminum rod?

(a)

1.4 mm

(b)

2.8 mm

(c)

4.2 mm

(d)

5.6 mm

Copper Wire metals and burns out when the current increases above______

(a)

5 A

(b)

10 A

(c)

25 A

(d)

25 A

Two identical coils, each with N turns and radius R are placed coaxially at a distance R as shown in the figure. If I is the current passing through the loops in the same direction, then the magnetic field at a point P at a distance of R/2 from the centre of each coil is _____.
 

(a)

\(\frac { 8N{ \mu }_{ ° }I }{ \sqrt { 5 } R } \)

(b)

\(\frac { 8N{ \mu }_{ ° }I }{ { 5 }^{ 3/2 }R } \)

(c)

\(\frac { 8N{ \mu }_{ ° }I }{ { 5 }R } \)

(d)

\(\frac { 4N{ \mu }_{ ° }I }{ \sqrt { 5 } R } \)

The direction of the magnetic force on a positive charge moving in a magnetic field is given by ________________.

(a)

thumb rule

(b)

left hand rule

(c)

right hand rule

(d)

cork screw rule

The heat developed in half a minute in a resistor of resistance 5Ω is 15,000 joules. The current through the resistor is _______________.

(a)

5 ampere

(b)

100 ampere

(c)

40 ampere

(d)

10 ampere

The magnetic declination for chennai is _______

(a)

-1° 5'

(b)

1°8'

(c)

-1°8'

(d)

1°5'

A circular coil with a cross-sectional area of 4 cm² has 10 turns. It is placed at the centre of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm². The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?

(a)

7.54 μH

(b)

8.54 μH

(c)

9.54 μH

(d)

10.54 μH

In an a.c. dynamo, the induced current is _________ in nature.

(a)

alternating

(b)

increasing

(c)

decreasing

(d)

constant

Gamma rays are used in the treatment of __________

(a)

cancer

(b)

Polio

(c)

AIDS

(d)

Tuberculosis

An object is placed in front of a convex mirror of focal length off and the maximum and minimum distance of an object from the mirror such that the image formed is real and magnified.

(a)

2f and c

(b)

c and \(\infty\)

(c)

f and O

(d)

None of these

The wavelength λ_e of an electron and λ_p of a photon of same energy E are related by _____.

(a)

λ_p ∝ λ_e

(b)

\({ \lambda }_{ p }∝ \sqrt { { \lambda }_{ e } } \)

(c)

\({ \lambda }_{ p }∝ \frac { 1 }{ \sqrt { { \lambda }_{ e } } } \)

(d)

\({ \lambda }_{ p }∝ { \lambda }_{ e }^{ 2 }\)

Sodium and copper have work functions of 2.3eV and 4.5eV respectively, then the ratio of the wavelengths is nearest to ___________.

(a)

1: 2

(b)

4: 1

(c)

2: 1

(d)

1: 4

Electrons when accelerated in a cyclotron acquires ________

(a)

zero mass

(b)

higher mass

(c)

zero velocity

(d)

uniform acceleration

Suppose an alpha particle accelerated by a potential of V volt is allowed to collide with a nucleus of atomic number Z, then the distance of closest approach of alpha particle to the nucleus is _____.

(a)

\(14.4\frac { Z }{ V } \mathring { A } \)

(b)

\(14.4\frac { V }{ Z } \mathring { A } \)

(c)

\(1.44\frac { Z }{ V } \mathring { A } \)

(d)

\(1.44\frac { V }{ Z } \mathring { A } \)

The explosion of hydrogen bomb is based on the principle of _________________.

(a)

uncontrolled fission reaction

(b)

nuclear fusion reaction

(c)

controlled fission

(d)

photo electric effect

The principle based on which a solar cell operates is______.

(a)

Diffusion

(b)

Recombination

(c)

Photovoltaic action

(d)

Carrier flow

In a video signal for transmission of picture what value of bandwidth is used in communication system?

(a)

2.4 MHz

(b)

4:2 MHz

(c)

24MHz

(d)

42 MHz

The transmitter in a RADAR is a high power ________.

(a)

cyclotron oscillator

(b)

magnetron oscillator

(c)

Hartley oscillator

(d)

simple harmonic oscillator

In actual practice, the range of uplink frequencies used is _________ GHz.

(a)

5.725 - 7.075

(b)

3.4 - 4.8

(c)

6 - 10

(d)

9 - 10