Physics-
General
Easy
Question
The moment of inertia of a body is I and its coefficient of linear expansion is if temperature of body rises by a small amount T. Then change in moment of inertia about the same axis –
- I T
- 2 I T
- 4 I T
The correct answer is: 2 I T
Let I = mr2
=
= 2 T
or 
Related Questions to study
Physics-
A rod of mass m and length l is hinged at one of its end A as shown in figure. A force F is applied at a distance x from A. The acceleration of centre of mass (a) varies with x as –
A rod of mass m and length l is hinged at one of its end A as shown in figure. A force F is applied at a distance x from A. The acceleration of centre of mass (a) varies with x as –
Physics-General
Physics-General
Physics-
A loop of radius 3 meter and weighs 150 kg. It rolls along a horizontal floor so that its centre of mass has a speed of 15 cm/sec. How much work has to be done to stop it –
A loop of radius 3 meter and weighs 150 kg. It rolls along a horizontal floor so that its centre of mass has a speed of 15 cm/sec. How much work has to be done to stop it –
Physics-General
Physics-
Two loops P and Q are made from a uniform wire. The radii of P and Q are r1 and r2 respectively, and their moments of inertia are I1 and I2 respectively. If I2 = 4I1 , then 
equals –
Two loops P and Q are made from a uniform wire. The radii of P and Q are r1 and r2 respectively, and their moments of inertia are I1 and I2 respectively. If I2 = 4I1 , then equals –
Physics-General
Physics-
The angular speed of rotating rigid body is increased from 4 to 5 . The percentage increase in its K.E. is –
The angular speed of rotating rigid body is increased from 4 to 5 . The percentage increase in its K.E. is –
Physics-General
Physics-
A particle performs uniform circular motion with angular momentum 'L'. If the frequency of particles motion is halved and its KE is doubled then the angular momentum becomes –
A particle performs uniform circular motion with angular momentum 'L'. If the frequency of particles motion is halved and its KE is doubled then the angular momentum becomes –
Physics-General
Physics-
What must be the relation between length 'L' and radius 'R' of the cylinder if its moment of inertia about its axis is equal to that about the equatorial axis ?
What must be the relation between length 'L' and radius 'R' of the cylinder if its moment of inertia about its axis is equal to that about the equatorial axis ?
Physics-General
Physics-
A solid sphere of mass M and radius R is placed on a smooth horizontal surface. It is given a horizontal impulse J at a height h above the centre of mass and sphere starts rolling then, the value of h and speed of centre of mass are –
A solid sphere of mass M and radius R is placed on a smooth horizontal surface. It is given a horizontal impulse J at a height h above the centre of mass and sphere starts rolling then, the value of h and speed of centre of mass are –
Physics-General
Physics-General
Physics-
A square plate is kept in yz-plane. Then according to perpendicular axis theorem -
A square plate is kept in yz-plane. Then according to perpendicular axis theorem -
Physics-General
Physics-
A sphere of radius 'R' is rolling over a horizontal surface. All measurement are made with respect to surface over which sphere is rolling. Which of the following strictly confirms pure rolling motion of sphere over horizontal surface ?
A sphere of radius 'R' is rolling over a horizontal surface. All measurement are made with respect to surface over which sphere is rolling. Which of the following strictly confirms pure rolling motion of sphere over horizontal surface ?
Physics-General
Physics-
One end of a uniform rod of length l and mass m is hinged at A. It is released from rest from horizontal position AB as shown in figure. The force exerted by the rod on the hinge when it becomes vertical is -
One end of a uniform rod of length l and mass m is hinged at A. It is released from rest from horizontal position AB as shown in figure. The force exerted by the rod on the hinge when it becomes vertical is -
Physics-General
Physics-General
Physics-
When a circular coil of radius 1 m and 100 turns is rotated in a horizontal uniform magnetic field, the peak value of emf induced is 100 V. the coil is unwound and then rewound into a circular coil of radius 2 m. If it is rotated now, with the same speed, under similar conditions, the new peak value of emf developed is
When a circular coil of radius 1 m and 100 turns is rotated in a horizontal uniform magnetic field, the peak value of emf induced is 100 V. the coil is unwound and then rewound into a circular coil of radius 2 m. If it is rotated now, with the same speed, under similar conditions, the new peak value of emf developed is
Physics-General
Physics-
An average induced e.m.f. of 
appears in a coil when the current in it is changed from 
in opposite direction in 
. Self-inductance of the coil is
An average induced e.m.f. of appears in a coil when the current in it is changed from in opposite direction in . Self-inductance of the coil is
Physics-General
Physics-
A step down transformer, transforms a supply line voltage of 2200 V into 220 V. The primary coil has 5000turns. The efficiency and power transmitted by the transformer are 90% and 8 kW respectively. Then the power supplied is
A step down transformer, transforms a supply line voltage of 2200 V into 220 V. The primary coil has 5000turns. The efficiency and power transmitted by the transformer are 90% and 8 kW respectively. Then the power supplied is
Physics-General
Physics-
An e.m.f. of 
is induced in a given coil when the current in it changes at the rate of 
. The self inductance of the coil is
An e.m.f. of is induced in a given coil when the current in it changes at the rate of . The self inductance of the coil is
Physics-General
Physics-
Two concentric coils each of radius equal to 
are placed at right angles to each other. 
and
are the currents flowing in each coil respectively. The magnetic induction in 
at the centre of the coils will be
Two concentric coils each of radius equal to are placed at right angles to each other. and are the currents flowing in each coil respectively. The magnetic induction in at the centre of the coils will be
Physics-General
