Question: When a light wave is reflected from a mirrior, there is a change in its
1. velocity
2. frequency
3. wavelength
4. amplitude
Answer: 4
Question: In AC circuits, AC meters measure
1. mean values
2. peak values
3. mean square values
4. rms values
Answer: 4
Question: Effect of increasing temperature on resistance of semiconductor is—
1. Increasing
2. No change
3. Decreasing
4. First increasing then decreasing
Answer: 3
Question: If mass is increased by 2 times and velocity is increased by 3 times of a body then its momentum will be increased by —
1. 2 times
2. 3/2 times
3. 3 times
4. 6 times
Answer: 4
Question: For what colour of light refractive index of glass is minimum?
1. Yellow
2. Red
3. Blue
4. Violet
Answer: 2
Question: Newton’s laws of motion are valid in —
1. Rotating frame of reference
2. In all frame of reference
3. Non-inertial frame of reference
4. Inertial frame of reference
Answer: 4
Question: Many elements have non-integral atomic masses because —
1. Their isotopes have non-integral masses
2. They have isotopes
3. Their isotopes have different masses
4. The constituents neutrons, protons and electrons combine to give fractional masses
Answer: 1
Question: In which of the following processes of transmission of heat material medium is not required —
1. Radiation
2. Conduction
3. Convection
4. Conduction and convection
Answer: 1
Question: At 4 degree C, volume of a certain mass of water is —
1. Minimum
2. Increased by 1/12th part of its volume at 0° C
3. Maximum
4. Remains same as the volume at 0° C
Answer: 1
Question: Mach number is the ratio of —
1. Velocity of sound and velocity of a body
2. Velocity of two particles
3. Velocity of a body and velocity of sound
4. Frequency of two vibrating bodies
Answer: 1
Question: X-ray is —
1. Electromagnetic wave
2. The flow of positive charge
3. The flow of neutral practices
4. The flow of electron
Answer: 1
Question: The direction of vibration of practices with respect to wave direction in transverse wave is —
1. 30 degree
2. 45 degree
3. Right angle
4. Parallel
Answer: 1
Question: The minimum distance between an object and its real image in a convex lens is –
1. Less than 4f
2. Equal to 2f
3. Equal to 4f
4. More than 4f
Answer: 2
Question: Two copper wires A and B have the same weight and the radius of B is half that of A. The ratio Ra/Rb of their resistances is –
1. 1/8
2. 1/2
3. 1/16
4. 1/4
Answer: 4