KEAM Paper 1 Mock Test - 7 - JEE MCQ

We have a galvanometer of resistance 25 Ω. It is shunted by a 2.5 Ω wire. The part of total current that flows through the galvanometer is given as

Cathode rays are produced when the pressure is of the order of

Light appears to travel in a straight line because

Which of the following rays has minimum frequency?

Three point charges 1C, 2C, − 2C are placed at the vertices of an equilateral triangle of side one metre. The work done by an external force to increase the separation of the charges to 2 metres in joules is( ∈ 0 is permittivity of air.

Capacitance of a capacitor becomes 7/6 times its original value if a dielectric slab of thickness, t = 2/3 d is introduced in between the plates. 'd' is the separation between the plates. The dielectric constant of the dielectric slab is

A space ship is launched into a circular orbit of radius R close to surface of earth. The additional velocity to be imparted to the space ship in the orbit to overcome the earth's gravitational pull is [g - acceleration due to gravity]

The mass of the moon is 1/81 of the earth but the gravitational pull is 1/6 of the earth. It is due to the fact that

The radiant energy from the sun incident normally at the surface of earth is 20 kcal/m² min. What would have been the radiant energy incident normally on the earth, if the sun had a temperature twice of the present one

A black body, at a temperature of 227ºC, radiates heat at a rate of 84 J-m⁻²-s⁻¹. When its temperature is raised to 727ºC, the heat radiated by it in J-m⁻²-s⁻¹ will be

Two balls each of mass 60 g moving in opposite directions with speeds 4 m−s⁻¹ collide and rebound with the same speed. The change in momentum will be

A voltmeter of resistance 20000 Ω reads 5 volt. To make it read 20 volt, the extra resistance required is

Thye position x of a particle varies with time, t, as x = at²-bt³. The acceleration of the particle will be zero at time t is equal to

A particle is executing simple harmonic motion with an amplitude of 2 cm and angular frequency 100π rad-s⁻¹. The maximum acceleration of the particle is

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A):When a ball is thrown upwards, its momentum first decreases and then increases.
Reason(R):Law of conservation of momentum is not followed is this process.

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Pressure in a bubble (σ) in an atmosphere of pressure P₀ is   where r is the radius.
Reason(R): 4σ/r is the excess pressure due to two surfaces exposed to the atmosphere.

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Gravitational field intensity at the centre of ring is zero.
Reason(R): Net force at the centre of ring is zero.

Helium gas is filled in a closed vessel (whose coefficient of thermal expansion is negligible). When it is heated from 300 K to 600 K, then average kinetic energy of helium atoms will be

A soap bubble (S.T.30 dyne/cm) has radius of 1 cm. The work done is doubling its radius would be

A source and an observer move away in opposite directions with speed 10 ms^-1, each with respect to ground. Apparent frequency is 1950 Hz. If velocity of sound is 340.5 ms^-1, the natural frequency is

A convex lens of focal length 40 cm is in contact with a concave lens of focal length 25 cm. The power of combination is

An automobile engine develops 100 kW when rotating at a speed of 1800 rev-min⁻¹. What torque does it deliver?

The potential energy of a particle with displacement X is U(X). The motion is simple harmonic, when (K is a positive constant)

Work done by 0.1 mole of a gas at 27ºC when it expands to double its volume at constant pressure is (assume R=2 cal mole^-1 K^-1)

A copper block of mass 4 kg is heated in a furnance to a temperature 425ºC and then placed on a large ice block. The mass of ice that will melt in this process will be (Specific heat of copper=500 J-kg⁻¹-ºC⁻¹ and heat of fusion of ice = 336 kJ-kg⁻¹).

Length, breadth and thickness of a block of wood are measured and following results are obtained. These are l=(25.12 0.01) cm, b=(20.150.01)cm, t=(15.280.01) cm. The percentage error in the volume of the block is

To demonstrate the phenomenon of interference we require two sources which emit radiations of