CBSE
Multiple Choice QuestionsAssertion: Work done in uniform circular motion is zero.
Reason: Force is always directed along displacement.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If assertion is false but reason is true.
A 0.5 kg ball moves in a circle of radius 0.4 m at a velocity of 4 m/s. The centripetal force on the ball is
10 N
20 N
40 N
80 N
A ball is moving in a circular path of radius 5 m. If tangential acceleration at any instant is 10 m/s and the net acceleration makes an angle 30° with the centripetal acceleration, then the instantaneous speed is
Assertion: It is difficult to move a cycle along the road with its brakes on.
Reason: Sliding friction is greater than rolling friction.
If both the assertion and reason are true and reason is a correct explanation of the assertion.
If both assertion and reason are true but assertion is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both assertion and reason are false.
A particle is revolving in a circle of radius R. If the force acting on it is inversely proportional to R, then the time period is proportional to
R
R2
1/R
1/R2
Assertion: In an elastic collision of two billiard balls, the total kinetic energy is conserved during the short time of oscillation of the balls (i.e. when they are in contact).
Reason: Energy spent against friction does not follow the law of conservation of energy.
If both the assertion and reason are true and reason is a correct explanation of the assertion.
If both assertion and reason are true but assertion is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both assertion and reason are false.
Assertion: The driver in a vehicle moving with a constant speed on a straight road is in a noninertial frame of reference.
Reason: A reference frame in which Newton's laws of motion are applicable is non-inertial.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Three different objects m1 , m2 and m3 to fall from rest and from the same point O along three different frictionless paths. The speeds of the three objects, on reaching the ground, will be in the ratio of
m1 : m2 : m3
1 : 1 : 1
m1 : 2 m2 : 3m3
If mass of an atom M moving with speed v, what will be its speed after the emission of an α-particle is zero?
A road is 8 m wide. Its radius of curvature is 40 m. The outer edge is above the lower edge by a distance of 1.2 m. This road is most suited for a velocity of
5.7 m/s
7.7 m/s
36.1 m/s
9.7 m/s
