If r_p = 3 x 10³ ohm and gm = 20 m. mho if triode is used as an amplifier and RL = 6 kohm, then voltage amplification is

(1) 40
(2) 60
(3) 20
(4) 30

A stone falls under gravity. It covers distances h1, h2, h3 in the first 5 seconds, next 5 seconds and the next 5 seconds respectively. The relation between h₁, h₂ ,h₃ is.
1) h₁ =2h₂ =3h₃
2) h₁ = h₂/3 = h₃/5
3) h₂ =3h₁ and h₃ = 3h₂
4) h₁ =h₂ =h₃

A metal rod expands by 1.00 mm when it is heated from 20 C to 80 C. Another rod of the same material, twice as long as the first at 20 C is heated from 20C to 50 C. The second rod will expand by
 
 (1) 0.25 mm
 (2) 0.50 mm
 (3) 1.00 mm
 (4) 2.00 mm

A square conducting coil of area =100cm² is placed normally inside a uniform magnetic field of 10³ Wbm⁻². The magnetic flux linked with the coil is ____________ Wb.

1) 10
2) 10⁻⁵
3) 10⁵
4) 0

Relative permeability of iron is 5500. Its magnetic susceptibility is:

 1) 5201

 2) 5200 ´ 10^-2

3) 5499

4) 5200 ´ 10²

A student is using a convex lens of focal length 10 cm to study the image formation by a convex lens for the various positions of the object. In one of his observations, he may observe that when the object is placed at a distance of 20 cm from the lens, its image is formed at (select the correct option)

1) 20 cm on the other side of the lens and is of the same size, real and erect.
2) 40 cm on the other side of the lens and is magnified, real and inverted
3) 20 cm on the other side of the lens and is of the same size, real and inverted.
4) 20 cm on the other side of the lens and is of the same size, virtual and erect. 

 A 240-Volt appliance draws 15A of current for a period of 2 hours. How much energy in kilowatt-hours does it consume?

1) 7.2

2) 2 .6 x10⁷ 

3) 7200

4) 3600

 A ball of mass m attached to the end of a string revolves in a vertical circle of radius R. When the ball is at the top of the circle it is moving horizontally with a speed v. What is the tension in the string when the ball is at the top of the circle?

1) (mv² / R) -mg

2) mv²/ R

3) 0

4) mg

A galvanometer with a coil resistance of 100 Ω gives a full scale deflection when a current of 1 mA is passed through it. The resistance of the shunt needed in ohm to convert this galvanometer into an ammeter of range 10 A is nearly

1) 0.01
2) 0.001
3) 0.1
4) 0.099

Two infinitely long straight conductors which are held parallel to each other at a distance 0.4m carry currents 20A and 10A in the same direction. The magnetic induction at a point midway between them is 

1) 10⁻⁵ T
2) 3×10⁻⁵ T
3) 2×10⁻⁵ T
4) 10⁻⁶ T