It takes 16 min to boil some water in an electric kettle. Due to some defect it becomes necessary to remove 10% turns of the heating coil of the kettle. After repairs, how much time will it take to boil the same mass of water?

1) 17.7 min
2) 14.4 min
3) 20.9 min
4) 13.7 min

A particle of unit mass undergoes one-dimensional motion such that its velocity varies according to v(x) = βx-2n, where β and n are constants and x is the position of the particle. The acceleration of the particle as a function of x, is given by
1) -2nβ² x^-4n+1
2) -2nβ² x^-2n-1
3) -2nβ² x^-4n-1
4) -2β² x^-2n+1

A vehicle travels a distance of 160 km in 5 hours. The average speed is
 
 (1) 32 km/hr
 (2) 40 km/hr
 (3) 80 km/hr
 (4) 165 km/hr

If the escape velocity of a rocket from the surface of the Earth is ve , then the escape velocity of the same rocket from the surface of a planet whose acceleration due to gravity as well as radius are 5 times that of the Earth is
 
 1) v_e / 5
 2) 5 v_e
 3) 25 v_e
 4) v_e

The magnetic moment of a short bar magnet is 2 Am2. The magnetic field at a point 1 m away it in a direction making an angle 60o with its magnetic moment is /;

1) √5 ?×10⁻⁷ T
2) 10⁻⁷ T
3) √7 ?×10⁻⁷ T
4) 7×10⁻⁷ T

The dimension of resistivity are:
1. ML² T^-1 Q^-1
2.ML³ T Q^-2
3. ML³ T^-1 Q^-2
4.ML³ TQ^-1

Amplitude of a wave is represented by  $$A=\frac{c}{a+b-c}$$ Then resonance will occur when

1) b = -c/2
2) b = 0 and a = c
3) b = - a/2
4) None of these

Two charges of 50μC and 100μC1 are separated by a distance of 0.6 m0.6 m. The intensity of electric field at a point midway between them is :

1) 50 ×10⁶V/m
2) 5 ×10⁶V/m
3) 10 ×10⁶V/m
4) 10 ×10^-6V/m

Which of the following demonstrates that earth has a magnetic field?

(1) Earth is a planet rotating about the North-South axis.
(2) The intensity of cosmic rays (stream of charged particles coming particle coming from outer space) is more at the poles than at the Equator.
(3) A large quantity of iron-ore is found in the earth.
(4) The earth is surrounded by an ionosphere (a shell of charged particles)

A metal surface of work function 1.07 eV is irradiated with light of wavelength 332 nm. The retarding potential required to stop the escape of photo electron is 

1) 4.81eV
2) 3.74eV
3) 2.65eV
4) 1.07eV